DE CHAZAL DU MEE BUSINESS SCHOOL AUGUST 2003 MOCK EXAMINATIONS IOP 201-Q (INDUSTRIAL PSYCHOLOGICAL RESEARCH)

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1 DE CHAZAL DU MEE BUSINESS SCHOOL AUGUST 003 MOCK EXAMINATIONS IOP 01-Q (INDUSTRIAL PSYCHOLOGICAL RESEARCH) Time: hours READ THE INSTRUCTIONS BELOW VERY CAREFULLY. Do not open this question paper until you have been told to do so by the invigilator. ANSWER ALL QUESTIONS. Section A consists of 0 multiple-choice questions, each question carrying one mark. NO negative marking will be applied. Give your answers on the multiple-choice answer sheet provided. Section B consists of 4 structured questions. The marks are shown in brackets []. Silent and non-programmable calculators may be used. The total number of marks available is 95. This QUESTION PAPER consists of TEN printed pages, including (1) a list of statistical formulae and () a standard normal table. [Turn over

2 SECTION A This section consists of 0 multiple-choice questions. Each question carries one mark. Please indicate your answer by inserting a cross ( ) in the appropriate box in the provided answer sheet. ANSWER ALL QUESTIONS. 1. If you want to study the effect of hormonal changes in adolescent boys, your population would be A. All people in the world. B. All adolescent males. C. All adolescents. D. All males.. Which of the following is most likely to be measured categorically? A. Species of dogs appearing in the Sunday comics. B. Level of authoritarianism in a sample of public accountants. C. Weight gain in first year college students. D. Deterioration in driving performance under the influence of alcohol. 3. Which of the following is the appropriate pairing? A. Population: statistic; Sample: parameter. B. Population: statistic; Statistic: sample. C. Population: parameter; Sample: statistic. D. Parameter: statistic; Sample: population. 4. Which of the following best illustrates the conclusions that statisticians draw from experiments? A. Y = 1X + 3X 7 B. The average of the sample is 1.4. C. The Gross National product increased by points last year. D. Male teenage delinquents show higher levels of testosterone on average than do male non-delinquents. 5. When given a cup of coffee before a race, a sample of runners was found to run the race faster. If we then conclude that on average runners run faster after drinking coffee, this would be an example of A. An illogical inference. B. A statistical inference. C. An inferential inference. D. A descriptive inference.

3 3 6. Without a random sample A. We cannot estimate the parameters of a population. B. Calculate statistics. C. Collect quantitative data. D. Consult a decision tree to decide on an appropriate statistical procedure. 7. Calculate X with X, X 5, Y and Y 3. A. 9. B. 49. C. 11. D = = 1 = = 8. If we are comparing the adrenaline scores of children who live near an airport with those who live away from an airport, the dependent variable is A. Location. B. Stress. C. Adrenaline. D. Distance from the airport. 9. The following set of data was recorded: Score Frequency These data would most likely be characterized as A. Positively skewed. B. Negatively skewed. C. Normal. D. Uniformly distributed. 10. If the distribution of the ages of people were positively skewed, which of the following is most likely correct? A. There are about the same number of young as old people. B. There are more old people than young people. C. There are more young people than old people. D. None of the above. [Turn over

4 4 11. For the set of data 5, 9, 5, 5,, 4, the mean is closest to A. 4. B. 5. C D If we were interested in studying salaries in the national Basketball Association, the least useful measure of the typical salary would be the A. Median. B. Mean. C. Lowest. D. Range. 13. Which of the following statements about the mode is false? A. It can be calculated algebraically. B. It must be an actual score that occurred in the data set. C. It can consist of more than one number. D. All the above are true. 14. When a distribution is symmetric, which of the following are always equal? A. Mean and median. B. Mean and mode. C. Median and mode. D. Mean, median and mode. 15. The normal distribution is A. A distribution with a clearly known shape and other properties. B. More frequently observed for the distribution of small sample sizes. C. Characterised by a high degree of skewness. D. The distribution that we would expect for the salaries of basketball players. 16. The tables of the standard normal distribution contain only positive values of z because A. We aren t interested in negative values of z. B. Probabilities can never be negative. C. The distribution is symmetric. D. z can take on only positive values.

5 5 17. If we have data that have been sampled from a population that is normally distributed with a mean of 50 and a standard deviation of 10, we would expect that 95% of our observations would lie in the interval that is approximately A B C D Where is subjective probability most likely to be invoked? A. In setting the point spread in football. B. In playing Russian roulette. C. In deciding if tomorrow will be a good day. D. In calculating your best strategy in poker. 19. Two events are mutually exclusive when A. The occurrence of one event is independent of the occurrence of the other. B. Both events are equally likely to occur. C. The occurrence of one event precludes the occurrence of the other. D. The first event precedes the second event. 0. If we are interested in the probability that you will be depressed if you have experienced a great deal of stress in the past month, we are talking about A. A conditional probability. B. Independence. C. A joint probability. D. An additive probability. [Turn over

6 6 SECTION B This section consists of 4 structured questions. The marks are shown in brackets []. Please indicate your answer by inserting a cross ( ) in the appropriate box in the provided answer sheet. ANSWER ALL QUESTIONS DCDM Business School students were asked to evaluate their Statistics lecturer on a 10-point scale. The results of this exercise are tabulated below. Evaluation of lecturer Number of students (f) (on a 10-point scale) (a) (b) Reflect the above data by drawing a histogram and a frequency polygon on the same axes. [5 +5] Describe, without any calculation, the properties of the above distribution in terms of (i) Central tendency, [] (ii) Skewness and [] (iii) Kurtosis. [] [Total = 16 marks]

7 7. An industrial psychologist tried to determine the relationship between the number of days that employees were absent from work and their personality. She suspected that employees who have low personality test scores would tend to be absent more often. Using a questionnaire that measured these two variables, namely absenteeism and personality, she obtained scores from 15 employees. These data are given in the table below. Employee Personality scores (X) Absenteeism (Y) A 90 1 B 68 4 C 70 3 D 59 6 E 74 4 F 88 G 83 3 H 80 0 I 90 1 J 95 1 K 78 5 L 81 3 M 86 N 75 8 O 77 4 (a) Calculate the mean, median and mode personality scores. [ ] (b) Calculate the variance and standard deviation for the personality scores. [5 + ] (c) (i) Draw a scatter of the two sets of data. [5] (ii) Calculate the Pearsonian correlation coefficient and interpret your result. [4 + ] (iii) Find the percentage of common variance between the two sets of scores and illustrate it diagrammatically. [ + 3] (d) (i) Find the equation of the least-squares regression line for the data. [6] (ii) Calculate the expected absenteeism for a worker who has a personality test score of 70. Discuss about the reliability of your forecast. [ + ] [Total = 39 marks] [Turn over

8 8 3. The heights of men, X, in a population of 00 men, follow a normal distribution with mean 170 cm and variance 64 cm. (a) Calculate the corresponding z-score for a man with a height of 185 cm. [] (b) Calculate the corresponding z-score for a man with a height of 157 cm. [] (c) Determine the proportion of men with heights exceeding 157 cm. [3] (d) Determine the number of men with heights between 157 cm and 185 cm. [4] [Total = 11 marks] 4. A student has to sit for two examination papers (1 and ). The probability that he passes Paper 1 is If he passes Paper 1, the probability that he passes Paper is If he fails Paper 1, the probability that he passes Paper is 0.3. Find the probability that (a) He passes Paper. [4] (b) He passed Paper 1 given that he passed Paper. [5] [Total = 9 marks] END OF PAPER

9 9 LIST OF STATISTICAL FORMULAE Measures of location X X = N Measures of variability S X = X ( X ) N N 1 Correlation Pearson r = n xy x y { n x ( x) } n y ( y) { } Spearman R = 6 d n( n 1) 1 Regression Least-squares line Y ˆ = a + bx b = n xy x y n x ( x) a = Y bx

10 10 Normal distribution (Cumulative probabilities) P[Z < z] Z ~ N(0,1) z z-value Second decimal place Third decimal place ADD

11 11 DCDM BUSINESS SCHOOL MOCK EXAMINATIONS AUGUST 003 BASIC STATISTICS (IOP 01-Q) ANSWER SHEET IMPORTANT Fill the required details below in BLOCK letters. SURNAME OTHER NAME(S) READ ALL THE INSTRUCTIONS IN THE QUESTION PAPER VERY CAREFULLY BEFORE ANSWERING. [Turn over

12 1 SECTION A Please insert a cross ( ) in the appropriate box to indicate the answer that you think is correct. NO negative marking will be applied. (A) (B) (C) (D) (A) (B) (C) (D) (Do not forget to fill in your name overleaf.) GOOD LUCK!