SAMPLE QUESTIONS. Research Methods II - HCS 6313
|
|
- Damon Garrison
- 5 years ago
- Views:
Transcription
1 SAMPLE QUESTIONS Research Methods II - HCS 6313 This is a (small) set of sample questions. Please, note that the exam comprises more questions that this sample. Social Security Number: NAME: IMPORTANT NOTICE. Your answers must be placed in the spaces provided. Use the amount of space provided as an indication of the maximum length of answer that is expected. You may want to do your your calculations on scratch paper before writing them on the exam, but make sure you show all your calculations on the exam paper. Answers placed elsewhere than in the spaces provided will not be considered. Do not add any loose sheets. 1. (00 points) For each of the following multiple choice questions, select one and only one response (the response that is the most correct). a. A frequency distribution in which most scores are concentrated around the center and which is symmetrical about its midpoint is a: a. probability distribution b. normal distribution c. Monte Carlo distribution d. all of the above b. Gamay, who is a developmental psychologist, measures how responsive a mother is to her infant by rating the mother s behavior on a 10-point scale. He also obtains a measure of the strength of the infant attachment to the mother. He finds that as maternal responsiveness increases so does the strength of attachment. This an example of a(n) a. negative correlation b. inverse experimental mortality c. prediction d. positive correlation 2. (00 points) The staff at the student coffee house are trying to find out whether to continue serving their current blend of morning coffee. The customers are asked to indicate whether they like the particular roast of coffee beans or not by checking off either the YES or NO box on a slip of paper they are given when ordering their coffee. A total of 100 people completed the survey. The results shows that 60 people indicated their preference for the coffee that is currently being served. Can the staff of the coffee house consider this results reliable? This asks for a Binomial Test. The problem is to find the probability of finding 60 or more out of 100. If you are really patient you can compute this probability using the binomial distribution. A shorter way of doing is to use the normal approximation. This means that we need to transform the score of 60 out of 100 into a Z-score and then use the Z to N(Z) Table in order to find the probability associated with this Z-score. The Z-score is obtained as Z = (Y.5) M Y σ Y (Y.5) N P = = (60.5) = N P (1 P) = = 1.9. If we use the Z to N(Z) Table, we find that p(z) =.0287, (for a one-tail test) and therefore we can reject the null hypothesis at α =.05, but not at α =.01. So at α =.05 we accept that the customers prefer the new coffee. (food for thought: Would we have reached the same conclusions with a two-tailed test? What would have happened without the correction of continuity?). But at α =.01, we are forced to suspend the judgement and declare that we don t know. 1
2 2 3. (00 points ) Marie & Antoinette (1789) report that the correlation between wages and number of cakes eaten is equal to.6. Their data came from 15 (revolutionary) subjects. What statistical conclusion can they draw? Justify your answer. The question here is to find if this correlation is statistically significant. So we need to compute an F-ratio and find if this F ratio is large enough (i.e., rare enough ) to allow for the rejection of the null hypothesis. The F is computed with the usual formula (signal to noise... ): r df = 13 = 13 = 1 r = 9 13 = From the F table, we find that the critical values are (for ν 1 = 1 and ν 2 = 13): 4.67 (for α =.05) and 9.07 (for α =.01). Therefore,we can reject the null hypothesis at α =.05 but not at α =.01. So at α =.05, we can conclude that wealthier you are, the more cakes you eat (maybe because you can afford them!). 4. (00 points) There is (at best) one outstanding musician (a.k.a. a genius) per million human beings. According to some estimation (given by the Official Bureau of Improbable Statistics) 95% of musicians composed their first work before the age of 10 (their first work was in general good but not outstanding). However, composing at an earlier age is, by itself, quite remarkable, because less than one child in a thousand composes music of any interest before the age of 10. Your child, who is 9 year old, has just composed a nice song. This piece, actually is good enough to compare with the first work of a genius. Should you start thinking that you have a genius at home (justify your answer!)? This is a Bayes theorem question. What we want to find is the probability of begin a genius knowing that we have composed before the age of 10. Call A the even A = {Being a genius} and Call B the even B = {Composing before the age of 10}. This means that we want to find Pr{A B} from the probabilities that are given in text. From the text, we find that Pr{A} =.000,001, Pr{B} =.001, and Pr{B A} =.95. We need to plug all these values in the equation and we get: Pr{A B} = Pr{B A} Pr{A} Pr{B} = , = = = So we have less than a chance in one thousand that your child is a musical genius (Good Bye Mozart!).
3 3 5. (00 points ) Paire & Ternel (2000) are working on aggressive behaviors in children, and are particularly interested in the possibility of a relationship between relational aggression and overt aggression. They ask a group of 3rd and 5th graders to complete a peer assessment questionnaire in which the children are asked to describe a what the other children are doing during recess. From these reports, the investigators computed the number of overt and relational aggressive acts observed at recess during a two-week period. We have extracted the number of aggressive acts reported for six children. The results are given in the following table: Child A Child B Child C Child D Child E Child F W=Relational Y=Overt a. Draw a scatterplot of these data. 20 Overt and Relational Agressive Acts 18 A D Y (Overt Agression) C B 6 E F 4 2 Et voilà: W (Relational Agression) b. What is the value of the coefficient of correlation between the number of relational aggressive acts and the number of overt aggressive acts? An easy way of computing the coefficient of correlation is to create a table with all the information that we need. Here it is (NB: M W = 66 6 = 11, M Y = 72 6 = 12): Obs Name W w w 2 Y y y 2 y w 1 A B C D E F W SSW Y SSY SCP WY From this table, we can now compute the value of the coefficient of correlation ( rectangle divided by the square-root of the squares ): (W MW )(Y M Y ) r WY = (W MW ) 2 (Y M Y ) = SCP WY 90 = = 90 2 SSW SS Y = 3 4 =.75 c. How much variance do the variables (relational and overt aggression) have in common? The proportion of common variance between 2 variables is equal to the square of their coefficient of correlation. So the proportion of common variance is equal to r 2 =.75 2 = 32 4 = =.5625.
4 4 d. Is this result reliable? This means do a test! So we compute our usual F-ratio ( signal to noise... ): r2 9/16 df = 1 r2 7/16 4 = = If you are scared of fractions, you can get the same result with a bit more effort (and a pocket calculator): r2.752 df = 1 r = = When we compare this value with the critical value found in the table (critical F for ν 1 = 1 and ν 2 = 4; with α =.05, critical 7.71, with α =.01, critical 21.20). So we cannot reject the null hypothesis for any α level) e. Write the conclusion apa style. This is a possible way of writing:... We found that children who were reported (by their peers) to engage in overt aggressive behavior were also reported to engage in relational aggressive behavior r =.75. But this trend was not significant: r =.75, F(1,4) = 5.14, ns. Another possible way of writing is... We did not find a significant relations (correlation) between overt aggressive behaviors and relational aggressive behavior (as reported by the children s peers): r =.75, F(1,4) = 5.14, ns. (Incidentally, most experimenters would comment on the fact that their design had very low power because of the very small number of children participating in the experiment). 6. (00 points) To see if there is an age related change in altruism in children, Grunberg, Meycock, and Authery (1985) measured the number of pennies children donated to UNICEF when left alone. Six groups of respectively 3, 5, 7, 9, 11, and 13 year old children were given an opportunity to donate any or all of 10 pennies given to them by the experimenter. The number of pennies given by each child was recorded and analyzed. The results of a fictitious replication of this experiment are presented below. For simplicity, the number of children per group in this fictitious replication was equal to two and only four age groups were used: 3, 5, 7, 9. 3 yrs 5 yrs 7 yrs 9 yrs Child one Child two a. Knowing that the Pearson coefficient of correlation between age (X) and number of pennies given (Y ) is equal to.72 and that σ Y = 2.0 and σ X = 2.4, find the equation that predicts the number of pennies given from the age of the children. Here we need to use the alternative formula for b, namely: b = σ Y r XY = =.60 σ X 2.4 In order to compute a, we need to compute first the means of X and Y : M X = and then we need to plug these values in the formula for a: = 48 8 = 6 M Y = = = 3, a = M y b M x = 3 (0.60 6) = = So, the equation that gives the predicted number of pennies from the age of the child is Y = X or Number of Pennies = (0.60 Age ). (The older the children, the more they give; and they give.60 penny for each year of age).
5 5 b. Use the regression line equation to predict the number of pennies given by a 6 year old child We just need to use the previous equation with X = 6: Y = X = = 3. (i.e., we predict that a 6 year old will give 3 pennies). c. Evaluate if this equation gives a better prediction than chance alone at α =.01. (Take into account the fact that rŷ.y = r Y.X ) This means once again compute an F-ratio and perform a statistical test. The F ratio is computed with the standard ( signal to noise... ): r2.722 df = 1 r = = = When we compare this value with the critical value found in the table (critical F for ν 1 = 1 and ν 2 = 6; with α =.05, critical 5.99, with α =.01, critical 13.74). So, we can reject the null hypothesis for α =.05, but not for α =.01. d. Indicate the proportion of variance in number of pennies given explained by the age of the children This means computes r 2. Here it is: r 2 =.72 2 =.5184 So we will say that 52% of the variance of the number of pennies given can be explained by the age of the child.
6 6 7. (00 points ) de Ci and de La (2004) analyzed their data with SAS PROC REG. Below is the listing given by the program. **** SAS Listing **** A simple regression example The REG Procedure Model: MODEL1 Dependent Variable: Y Percent remembered Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model <.0001 Error Corrected Total Root MSE R-Square Dependent Mean Adj R-Sq Coeff Var Parameter Estimates Parameter Standard Variable Label DF Estimate Error t Value Intercept Intercept X Number of years passed Parameter Estimates Squared Semi-partial Variable Label DF Pr > t Type II SS Corr Type II Intercept Intercept 1 < X Number of years passed 1 < a. What is the equation predicting the dependent variable from the independent variable(s) (use their names): Percent Remembered = (Number of years passed ). b. With the alpha level of.01, is the prediction of the dependent variable better than chance? (write your answer apa style). One way of writing could be The number of years passed was found to predict the percent of material remembered by the participants: r 2 = 91, F(1,12) = , p <.01. An alternative way of writing: The number of years passed was found to predict the percent of material remembered by the participants: r 2 =.91, t(12) = 11.15, p <.01. c. What is the proportion of variance of the dependent variable explained by the independent variable(s)? The independent variable (Number of years passed) explains 91% of the variance of the dependent variable (percent remembered).
The t-statistic. Student s t Test
The t-statistic 1 Student s t Test When the population standard deviation is not known, you cannot use a z score hypothesis test Use Student s t test instead Student s t, or t test is, conceptually, very
More informationLab #12: Exam 3 Review Key
Psychological Statistics Practice Lab#1 Dr. M. Plonsky Page 1 of 7 Lab #1: Exam 3 Review Key 1) a. Probability - Refers to the likelihood that an event will occur. Ranges from 0 to 1. b. Sampling Distribution
More informationSTAT 350 Final (new Material) Review Problems Key Spring 2016
1. The editor of a statistics textbook would like to plan for the next edition. A key variable is the number of pages that will be in the final version. Text files are prepared by the authors using LaTeX,
More informationSampling Distributions: Central Limit Theorem
Review for Exam 2 Sampling Distributions: Central Limit Theorem Conceptually, we can break up the theorem into three parts: 1. The mean (µ M ) of a population of sample means (M) is equal to the mean (µ)
More informationt-test for b Copyright 2000 Tom Malloy. All rights reserved. Regression
t-test for b Copyright 2000 Tom Malloy. All rights reserved. Regression Recall, back some time ago, we used a descriptive statistic which allowed us to draw the best fit line through a scatter plot. We
More informationUNIVERSITY OF TORONTO Faculty of Arts and Science
UNIVERSITY OF TORONTO Faculty of Arts and Science December 2013 Final Examination STA442H1F/2101HF Methods of Applied Statistics Jerry Brunner Duration - 3 hours Aids: Calculator Model(s): Any calculator
More informationSTA 302 H1F / 1001 HF Fall 2007 Test 1 October 24, 2007
STA 302 H1F / 1001 HF Fall 2007 Test 1 October 24, 2007 LAST NAME: SOLUTIONS FIRST NAME: STUDENT NUMBER: ENROLLED IN: (circle one) STA 302 STA 1001 INSTRUCTIONS: Time: 90 minutes Aids allowed: calculator.
More information(a) The density histogram above right represents a particular sample of n = 40 practice shots. Answer each of the following. Show all work.
. Target Practice. An archer is practicing hitting the bull s-eye of the target shown below left. For any point on the target, define the continuous random variable D = (signed) radial distance to the
More informationSTAT 512 MidTerm I (2/21/2013) Spring 2013 INSTRUCTIONS
STAT 512 MidTerm I (2/21/2013) Spring 2013 Name: Key INSTRUCTIONS 1. This exam is open book/open notes. All papers (but no electronic devices except for calculators) are allowed. 2. There are 5 pages in
More informationECON 497 Final Exam Page 1 of 12
ECON 497 Final Exam Page of 2 ECON 497: Economic Research and Forecasting Name: Spring 2008 Bellas Final Exam Return this exam to me by 4:00 on Wednesday, April 23. It may be e-mailed to me. It may be
More informationLab # 11: Correlation and Model Fitting
Lab # 11: Correlation and Model Fitting Objectives: 1. Correlations between variables 2. Data Manipulation, creation of squares 3. Model fitting with regression 4. Comparison of models Correlations between
More informationAnalysis of Variance. Source DF Squares Square F Value Pr > F. Model <.0001 Error Corrected Total
Math 221: Linear Regression and Prediction Intervals S. K. Hyde Chapter 23 (Moore, 5th Ed.) (Neter, Kutner, Nachsheim, and Wasserman) The Toluca Company manufactures refrigeration equipment as well as
More informationBusiness Statistics. Lecture 10: Course Review
Business Statistics Lecture 10: Course Review 1 Descriptive Statistics for Continuous Data Numerical Summaries Location: mean, median Spread or variability: variance, standard deviation, range, percentiles,
More informationGeneral Linear Model (Chapter 4)
General Linear Model (Chapter 4) Outcome variable is considered continuous Simple linear regression Scatterplots OLS is BLUE under basic assumptions MSE estimates residual variance testing regression coefficients
More informationBlack White Total Observed Expected χ 2 = (f observed f expected ) 2 f expected (83 126) 2 ( )2 126
Psychology 60 Fall 2013 Practice Final Actual Exam: This Wednesday. Good luck! Name: To view the solutions, check the link at the end of the document. This practice final should supplement your studying;
More informationSimple Linear Regression: One Quantitative IV
Simple Linear Regression: One Quantitative IV Linear regression is frequently used to explain variation observed in a dependent variable (DV) with theoretically linked independent variables (IV). For example,
More informationSTAT 350: Summer Semester Midterm 1: Solutions
Name: Student Number: STAT 350: Summer Semester 2008 Midterm 1: Solutions 9 June 2008 Instructor: Richard Lockhart Instructions: This is an open book test. You may use notes, text, other books and a calculator.
More informationCorrelation and the Analysis of Variance Approach to Simple Linear Regression
Correlation and the Analysis of Variance Approach to Simple Linear Regression Biometry 755 Spring 2009 Correlation and the Analysis of Variance Approach to Simple Linear Regression p. 1/35 Correlation
More informationQuantitative Methods Final Exam (2017/1)
Quantitative Methods Final Exam (2017/1) 1. Please write down your name and student ID number. 2. Calculator is allowed during the exam, but DO NOT use a smartphone. 3. List your answers (together with
More informationST Correlation and Regression
Chapter 5 ST 370 - Correlation and Regression Readings: Chapter 11.1-11.4, 11.7.2-11.8, Chapter 12.1-12.2 Recap: So far we ve learned: Why we want a random sample and how to achieve it (Sampling Scheme)
More informationSTAT 3A03 Applied Regression With SAS Fall 2017
STAT 3A03 Applied Regression With SAS Fall 2017 Assignment 2 Solution Set Q. 1 I will add subscripts relating to the question part to the parameters and their estimates as well as the errors and residuals.
More informationModule 7 Practice problem and Homework answers
Module 7 Practice problem and Homework answers Practice problem, page 1 Is the research hypothesis one-tailed or two-tailed? Answer: one tailed In the set up for the problem, we predicted a specific outcome
More informationUNIVERSITY EXAMINATIONS NJORO CAMPUS SECOND SEMESTER 2011/2012
UNIVERSITY EXAMINATIONS NJORO CAMPUS SECOND SEMESTER 2011/2012 THIRD YEAR EXAMINATION FOR THE AWARD BACHELOR OF SCIENCE IN AGRICULTURE AND BACHELOR OF SCIENCE IN FOOD TECHNOLOGY AGRO 391 AGRICULTURAL EXPERIMENTATION
More information5. Let W follow a normal distribution with mean of μ and the variance of 1. Then, the pdf of W is
Practice Final Exam Last Name:, First Name:. Please write LEGIBLY. Answer all questions on this exam in the space provided (you may use the back of any page if you need more space). Show all work but do
More informationPaper: ST-161. Techniques for Evidence-Based Decision Making Using SAS Ian Stockwell, The Hilltop UMBC, Baltimore, MD
Paper: ST-161 Techniques for Evidence-Based Decision Making Using SAS Ian Stockwell, The Hilltop Institute @ UMBC, Baltimore, MD ABSTRACT SAS has many tools that can be used for data analysis. From Freqs
More informationSimple Linear Regression: One Qualitative IV
Simple Linear Regression: One Qualitative IV 1. Purpose As noted before regression is used both to explain and predict variation in DVs, and adding to the equation categorical variables extends regression
More informationChapter 1: Linear Regression with One Predictor Variable also known as: Simple Linear Regression Bivariate Linear Regression
BSTT523: Kutner et al., Chapter 1 1 Chapter 1: Linear Regression with One Predictor Variable also known as: Simple Linear Regression Bivariate Linear Regression Introduction: Functional relation between
More informationPLS205!! Lab 9!! March 6, Topic 13: Covariance Analysis
PLS205!! Lab 9!! March 6, 2014 Topic 13: Covariance Analysis Covariable as a tool for increasing precision Carrying out a full ANCOVA Testing ANOVA assumptions Happiness! Covariable as a Tool for Increasing
More information3 Variables: Cyberloafing Conscientiousness Age
title 'Cyberloafing, Mike Sage'; run; PROC CORR data=sage; var Cyberloafing Conscientiousness Age; run; quit; The CORR Procedure 3 Variables: Cyberloafing Conscientiousness Age Simple Statistics Variable
More informationMulticollinearity Exercise
Multicollinearity Exercise Use the attached SAS output to answer the questions. [OPTIONAL: Copy the SAS program below into the SAS editor window and run it.] You do not need to submit any output, so there
More informationLecture notes on Regression & SAS example demonstration
Regression & Correlation (p. 215) When two variables are measured on a single experimental unit, the resulting data are called bivariate data. You can describe each variable individually, and you can also
More informationStat 20 Midterm 1 Review
Stat 20 Midterm Review February 7, 2007 This handout is intended to be a comprehensive study guide for the first Stat 20 midterm exam. I have tried to cover all the course material in a way that targets
More informationRelationships between variables. Visualizing Bivariate Distributions: Scatter Plots
SFBS Course Notes Part 7: Correlation Bivariate relationships (p. 1) Linear transformations (p. 3) Pearson r : Measuring a relationship (p. 5) Interpretation of correlations (p. 10) Relationships between
More informationSTAT 3900/4950 MIDTERM TWO Name: Spring, 2015 (print: first last ) Covered topics: Two-way ANOVA, ANCOVA, SLR, MLR and correlation analysis
STAT 3900/4950 MIDTERM TWO Name: Spring, 205 (print: first last ) Covered topics: Two-way ANOVA, ANCOVA, SLR, MLR and correlation analysis Instructions: You may use your books, notes, and SPSS/SAS. NO
More informationHYPOTHESIS TESTING. Hypothesis Testing
MBA 605 Business Analytics Don Conant, PhD. HYPOTHESIS TESTING Hypothesis testing involves making inferences about the nature of the population on the basis of observations of a sample drawn from the population.
More informationStatistics 5100 Spring 2018 Exam 1
Statistics 5100 Spring 2018 Exam 1 Directions: You have 60 minutes to complete the exam. Be sure to answer every question, and do not spend too much time on any part of any question. Be concise with all
More informationSTAT 350. Assignment 4
STAT 350 Assignment 4 1. For the Mileage data in assignment 3 conduct a residual analysis and report your findings. I used the full model for this since my answers to assignment 3 suggested we needed the
More informationPsych 10 / Stats 60, Practice Problem Set 5 (Week 5 Material) Part 1: Power (and building blocks of power)
Psych 10 / Stats 60, Practice Problem Set 5 (Week 5 Material) Part 1: Power (and building blocks of power) 1. A researcher plans to do a two-tailed hypothesis test with a sample of n = 100 people and a
More informationECON3150/4150 Spring 2016
ECON3150/4150 Spring 2016 Lecture 4 - The linear regression model Siv-Elisabeth Skjelbred University of Oslo Last updated: January 26, 2016 1 / 49 Overview These lecture slides covers: The linear regression
More informationHYPOTHESIS TESTING: SINGLE MEAN, NORMAL DISTRIBUTION (Z-TEST)
HYPOTHESIS TESTING: SINGLE MEAN, NORMAL DISTRIBUTION (Z-TEST) In Binomial Hypothesis Testing researchers generally ignore the actual numbers that are obtained on their measure. The Binomial Test for whether
More informationST505/S697R: Fall Homework 2 Solution.
ST505/S69R: Fall 2012. Homework 2 Solution. 1. 1a; problem 1.22 Below is the summary information (edited) from the regression (using R output); code at end of solution as is code and output for SAS. a)
More informationStatistics 512: Solution to Homework#11. Problems 1-3 refer to the soybean sausage dataset of Problem 20.8 (ch21pr08.dat).
Statistics 512: Solution to Homework#11 Problems 1-3 refer to the soybean sausage dataset of Problem 20.8 (ch21pr08.dat). 1. Perform the two-way ANOVA without interaction for this model. Use the results
More informationCh. 16: Correlation and Regression
Ch. 1: Correlation and Regression With the shift to correlational analyses, we change the very nature of the question we are asking of our data. Heretofore, we were asking if a difference was likely to
More informationLecture 11 Multiple Linear Regression
Lecture 11 Multiple Linear Regression STAT 512 Spring 2011 Background Reading KNNL: 6.1-6.5 11-1 Topic Overview Review: Multiple Linear Regression (MLR) Computer Science Case Study 11-2 Multiple Regression
More informationLecture 11: Simple Linear Regression
Lecture 11: Simple Linear Regression Readings: Sections 3.1-3.3, 11.1-11.3 Apr 17, 2009 In linear regression, we examine the association between two quantitative variables. Number of beers that you drink
More informationHypothesis testing: Steps
Review for Exam 2 Hypothesis testing: Steps Repeated-Measures ANOVA 1. Determine appropriate test and hypotheses 2. Use distribution table to find critical statistic value(s) representing rejection region
More information14.32 Final : Spring 2001
14.32 Final : Spring 2001 Please read the entire exam before you begin. You have 3 hours. No books or notes should be used. Calculators are allowed. There are 105 points. Good luck! A. True/False/Sometimes
More informationLecture 10: F -Tests, ANOVA and R 2
Lecture 10: F -Tests, ANOVA and R 2 1 ANOVA We saw that we could test the null hypothesis that β 1 0 using the statistic ( β 1 0)/ŝe. (Although I also mentioned that confidence intervals are generally
More informationExamination paper for TMA4255 Applied statistics
Department of Mathematical Sciences Examination paper for TMA4255 Applied statistics Academic contact during examination: Anna Marie Holand Phone: 951 38 038 Examination date: 16 May 2015 Examination time
More informationBusiness Statistics. Lecture 9: Simple Regression
Business Statistics Lecture 9: Simple Regression 1 On to Model Building! Up to now, class was about descriptive and inferential statistics Numerical and graphical summaries of data Confidence intervals
More informationHypothesis Testing. We normally talk about two types of hypothesis: the null hypothesis and the research or alternative hypothesis.
Hypothesis Testing Today, we are going to begin talking about the idea of hypothesis testing how we can use statistics to show that our causal models are valid or invalid. We normally talk about two types
More informationN J SS W /df W N - 1
One-Way ANOVA Source Table ANOVA MODEL: ij = µ* + α j + ε ij H 0 : µ = µ =... = µ j or H 0 : Σα j = 0 Source Sum of Squares df Mean Squares F J Between Groups nj( j * ) J - SS B /(J ) MS B /MS W = ( N
More informationRegression, part II. I. What does it all mean? A) Notice that so far all we ve done is math.
Regression, part II I. What does it all mean? A) Notice that so far all we ve done is math. 1) One can calculate the Least Squares Regression Line for anything, regardless of any assumptions. 2) But, if
More informationCorrelation & Simple Regression
Chapter 11 Correlation & Simple Regression The previous chapter dealt with inference for two categorical variables. In this chapter, we would like to examine the relationship between two quantitative variables.
More informationIntroduction to Linear Regression
Introduction to Linear Regression James H. Steiger Department of Psychology and Human Development Vanderbilt University James H. Steiger (Vanderbilt University) Introduction to Linear Regression 1 / 46
More informationREVIEW 8/2/2017 陈芳华东师大英语系
REVIEW Hypothesis testing starts with a null hypothesis and a null distribution. We compare what we have to the null distribution, if the result is too extreme to belong to the null distribution (p
More informationLecture 3: Inference in SLR
Lecture 3: Inference in SLR STAT 51 Spring 011 Background Reading KNNL:.1.6 3-1 Topic Overview This topic will cover: Review of hypothesis testing Inference about 1 Inference about 0 Confidence Intervals
More informationCorrelation. We don't consider one variable independent and the other dependent. Does x go up as y goes up? Does x go down as y goes up?
Comment: notes are adapted from BIOL 214/312. I. Correlation. Correlation A) Correlation is used when we want to examine the relationship of two continuous variables. We are not interested in prediction.
More informationMock Exam - 2 hours - use of basic (non-programmable) calculator is allowed - all exercises carry the same marks - exam is strictly individual
Mock Exam - 2 hours - use of basic (non-programmable) calculator is allowed - all exercises carry the same marks - exam is strictly individual Question 1. Suppose you want to estimate the percentage of
More informationHypothesis testing: Steps
Review for Exam 2 Hypothesis testing: Steps Exam 2 Review 1. Determine appropriate test and hypotheses 2. Use distribution table to find critical statistic value(s) representing rejection region 3. Compute
More informationa. YOU MAY USE ONE 8.5 X11 TWO-SIDED CHEAT SHEET AND YOUR TEXTBOOK (OR COPY THEREOF).
STAT3503 Test 2 NOTE: a. YOU MAY USE ONE 8.5 X11 TWO-SIDED CHEAT SHEET AND YOUR TEXTBOOK (OR COPY THEREOF). b. YOU MAY USE ANY ELECTRONIC CALCULATOR. c. FOR FULL MARKS YOU MUST SHOW THE FORMULA YOU USE
More informationMultiple Regression. More Hypothesis Testing. More Hypothesis Testing The big question: What we really want to know: What we actually know: We know:
Multiple Regression Ψ320 Ainsworth More Hypothesis Testing What we really want to know: Is the relationship in the population we have selected between X & Y strong enough that we can use the relationship
More informationThe t-test: A z-score for a sample mean tells us where in the distribution the particular mean lies
The t-test: So Far: Sampling distribution benefit is that even if the original population is not normal, a sampling distribution based on this population will be normal (for sample size > 30). Benefit
More informationSTATISTICS 110/201 PRACTICE FINAL EXAM
STATISTICS 110/201 PRACTICE FINAL EXAM Questions 1 to 5: There is a downloadable Stata package that produces sequential sums of squares for regression. In other words, the SS is built up as each variable
More informationMultiple Regression: Inference
Multiple Regression: Inference The t-test: is ˆ j big and precise enough? We test the null hypothesis: H 0 : β j =0; i.e. test that x j has no effect on y once the other explanatory variables are controlled
More informationCh. 7 Statistical Intervals Based on a Single Sample
Ch. 7 Statistical Intervals Based on a Single Sample Before discussing the topics in Ch. 7, we need to cover one important concept from Ch. 6. Standard error The standard error is the standard deviation
More informationPSY 216. Assignment 9 Answers. Under what circumstances is a t statistic used instead of a z-score for a hypothesis test
PSY 216 Assignment 9 Answers 1. Problem 1 from the text Under what circumstances is a t statistic used instead of a z-score for a hypothesis test The t statistic should be used when the population standard
More informationy = a + bx 12.1: Inference for Linear Regression Review: General Form of Linear Regression Equation Review: Interpreting Computer Regression Output
12.1: Inference for Linear Regression Review: General Form of Linear Regression Equation y = a + bx y = dependent variable a = intercept b = slope x = independent variable Section 12.1 Inference for Linear
More informationSection 3: Simple Linear Regression
Section 3: Simple Linear Regression Carlos M. Carvalho The University of Texas at Austin McCombs School of Business http://faculty.mccombs.utexas.edu/carlos.carvalho/teaching/ 1 Regression: General Introduction
More informationInference for Regression
Inference for Regression Section 9.4 Cathy Poliak, Ph.D. cathy@math.uh.edu Office in Fleming 11c Department of Mathematics University of Houston Lecture 13b - 3339 Cathy Poliak, Ph.D. cathy@math.uh.edu
More informationHypothesis testing I. - In particular, we are talking about statistical hypotheses. [get everyone s finger length!] n =
Hypothesis testing I I. What is hypothesis testing? [Note we re temporarily bouncing around in the book a lot! Things will settle down again in a week or so] - Exactly what it says. We develop a hypothesis,
More informationCategorical Data Analysis 1
Categorical Data Analysis 1 STA 312: Fall 2012 1 See last slide for copyright information. 1 / 1 Variables and Cases There are n cases (people, rats, factories, wolf packs) in a data set. A variable is
More informationECO220Y Simple Regression: Testing the Slope
ECO220Y Simple Regression: Testing the Slope Readings: Chapter 18 (Sections 18.3-18.5) Winter 2012 Lecture 19 (Winter 2012) Simple Regression Lecture 19 1 / 32 Simple Regression Model y i = β 0 + β 1 x
More informationLecture (chapter 13): Association between variables measured at the interval-ratio level
Lecture (chapter 13): Association between variables measured at the interval-ratio level Ernesto F. L. Amaral April 9 11, 2018 Advanced Methods of Social Research (SOCI 420) Source: Healey, Joseph F. 2015.
More informationSimple Linear Regression
Chapter 2 Simple Linear Regression Linear Regression with One Independent Variable 2.1 Introduction In Chapter 1 we introduced the linear model as an alternative for making inferences on means of one or
More informationMultiple Linear Regression
Multiple Linear Regression Simple linear regression tries to fit a simple line between two variables Y and X. If X is linearly related to Y this explains some of the variability in Y. In most cases, there
More informationCorrelation and Linear Regression
Correlation and Linear Regression Correlation: Relationships between Variables So far, nearly all of our discussion of inferential statistics has focused on testing for differences between group means
More informationPS2: Two Variable Statistics
PS2: Two Variable Statistics LT2: Measuring Correlation and Line of best fit by eye. LT3: Linear regression LT4: The χ 2 test of independence. 1 Pearson's Correlation Coefficient In examinations you are
More informationdf=degrees of freedom = n - 1
One sample t-test test of the mean Assumptions: Independent, random samples Approximately normal distribution (from intro class: σ is unknown, need to calculate and use s (sample standard deviation)) Hypotheses:
More informationBinary Logistic Regression
The coefficients of the multiple regression model are estimated using sample data with k independent variables Estimated (or predicted) value of Y Estimated intercept Estimated slope coefficients Ŷ = b
More informationSTAT Exam Jam Solutions. Contents
s Contents 1 First Day 2 Question 1: PDFs, CDFs, and Finding E(X), V (X).......................... 2 Question 2: Bayesian Inference...................................... 3 Question 3: Binomial to Normal
More informationIntroduction to Bayesian Statistics and Markov Chain Monte Carlo Estimation. EPSY 905: Multivariate Analysis Spring 2016 Lecture #10: April 6, 2016
Introduction to Bayesian Statistics and Markov Chain Monte Carlo Estimation EPSY 905: Multivariate Analysis Spring 2016 Lecture #10: April 6, 2016 EPSY 905: Intro to Bayesian and MCMC Today s Class An
More informationChapter 13 Correlation
Chapter Correlation Page. Pearson correlation coefficient -. Inferential tests on correlation coefficients -9. Correlational assumptions -. on-parametric measures of correlation -5 5. correlational example
More informationChs. 16 & 17: Correlation & Regression
Chs. 16 & 17: Correlation & Regression With the shift to correlational analyses, we change the very nature of the question we are asking of our data. Heretofore, we were asking if a difference was likely
More informationIn many situations, there is a non-parametric test that corresponds to the standard test, as described below:
There are many standard tests like the t-tests and analyses of variance that are commonly used. They rest on assumptions like normality, which can be hard to assess: for example, if you have small samples,
More informationStat 500 Midterm 2 12 November 2009 page 0 of 11
Stat 500 Midterm 2 12 November 2009 page 0 of 11 Please put your name on the back of your answer book. Do NOT put it on the front. Thanks. Do not start until I tell you to. The exam is closed book, closed
More informationSIMPLE REGRESSION ANALYSIS. Business Statistics
SIMPLE REGRESSION ANALYSIS Business Statistics CONTENTS Ordinary least squares (recap for some) Statistical formulation of the regression model Assessing the regression model Testing the regression coefficients
More informationIntroduction to Statistics for the Social Sciences Review for Exam 4 Homework Assignment 27
Introduction to Statistics for the Social Sciences Review for Exam 4 Homework Assignment 27 Name: Lab: The purpose of this worksheet is to review the material to be represented in Exam 4. Please answer
More informationExam Applied Statistical Regression. Good Luck!
Dr. M. Dettling Summer 2011 Exam Applied Statistical Regression Approved: Tables: Note: Any written material, calculator (without communication facility). Attached. All tests have to be done at the 5%-level.
More information1 Least Squares Estimation - multiple regression.
Introduction to multiple regression. Fall 2010 1 Least Squares Estimation - multiple regression. Let y = {y 1,, y n } be a n 1 vector of dependent variable observations. Let β = {β 0, β 1 } be the 2 1
More informationSwarthmore Honors Exam 2012: Statistics
Swarthmore Honors Exam 2012: Statistics 1 Swarthmore Honors Exam 2012: Statistics John W. Emerson, Yale University NAME: Instructions: This is a closed-book three-hour exam having six questions. You may
More informationA Little Stats Won t Hurt You
A Little Stats Won t Hurt You Nate Derby Statis Pro Data Analytics Seattle, WA, USA Edmonton SAS Users Group, 11/13/09 Nate Derby A Little Stats Won t Hurt You 1 / 71 Outline Introduction 1 Introduction
More information" M A #M B. Standard deviation of the population (Greek lowercase letter sigma) σ 2
Notation and Equations for Final Exam Symbol Definition X The variable we measure in a scientific study n The size of the sample N The size of the population M The mean of the sample µ The mean of the
More informationSTATISTICS 479 Exam II (100 points)
Name STATISTICS 79 Exam II (1 points) 1. A SAS data set was created using the following input statement: Answer parts(a) to (e) below. input State $ City $ Pop199 Income Housing Electric; (a) () Give the
More informationIntroduction to Econometrics. Review of Probability & Statistics
1 Introduction to Econometrics Review of Probability & Statistics Peerapat Wongchaiwat, Ph.D. wongchaiwat@hotmail.com Introduction 2 What is Econometrics? Econometrics consists of the application of mathematical
More informationFinal Exam. Question 1 (20 points) 2 (25 points) 3 (30 points) 4 (25 points) 5 (10 points) 6 (40 points) Total (150 points) Bonus question (10)
Name Economics 170 Spring 2004 Honor pledge: I have neither given nor received aid on this exam including the preparation of my one page formula list and the preparation of the Stata assignment for the
More informationCorrelation and Regression
Correlation and Regression Dr. Bob Gee Dean Scott Bonney Professor William G. Journigan American Meridian University 1 Learning Objectives Upon successful completion of this module, the student should
More informationOrdinary Least Squares Regression Explained: Vartanian
Ordinary Least Squares Regression Explained: Vartanian When to Use Ordinary Least Squares Regression Analysis A. Variable types. When you have an interval/ratio scale dependent variable.. When your independent
More informationStudent s t-distribution. The t-distribution, t-tests, & Measures of Effect Size
Student s t-distribution The t-distribution, t-tests, & Measures of Effect Size Sampling Distributions Redux Chapter 7 opens with a return to the concept of sampling distributions from chapter 4 Sampling
More informationFinal Exam - Solutions
Ecn 102 - Analysis of Economic Data University of California - Davis March 17, 2010 Instructor: John Parman Final Exam - Solutions You have until 12:30pm to complete this exam. Please remember to put your
More information