Honors Statistics. Daily Agenda

Transcription

1 Section 2.1 Describing Location in a Distribution Day 3 Linear Data Transformations Honors Statistics Daily Agenda 1. Review OTL C2#3 2. Introduce and practice data transformations 1

2 Askips are red - show the arithmetic for all Do practice MC A B C D E CONTINUE Reading and Notes Chapter 2 Section 2 page 103 to 127 NOTES TOOK ME 1 Hour Please start You Better CONTINUE Reading and Notes Chapter 2 Section 2 page 103 to 127 Yep... I am going to check your "starting" a) This student sent/ received 200 texts in the two-day period. Their text behavior is located at approximately the 80th percentile. This means that 80% of the students sent/received less than 200 texts during the twoday period. b) The median number of texts is the 50th percentile which is approximately 105 texts sent/received. 2

3 a) Maryland has approximately 13% foreign-born residents. This is approximately the 73rd% tile for the 50 states. b) The 30th%tile is approximately 4% of resident foreign-born. a) Q1 25th%tile is approximately $19 Q3 75th%tile is approximately $48 b) $19.50 is 26th %tile IQR =

4 z = 4.15 z = 4.26 Williams z = 4.07 All of the hitters were at least 4 standard deviation above their respective means but Ty Williams was the highest with z = = 4

5 a) 29 players... Brad is position number 23 so... = th %tile 75% of the player made less money than Brad made in the 2008 team /29 = z = Brad's salary is 0.79 standard deviations above the mean. X = X

6 Q1 25th%tile is approximately Q3 75th%tile is approximately IQR =

7 The distribution of travel times is not symmetric and is skewed to the right. The center is approximately at 20 minutes. The data spreads from 0 minutes to 90 minutes with a range of 90 minutes. The data should be analyzed using the 5 number summary. There are many gaps after 40 minutes and 2 to 5 potential outliers at the top end. 7

8 Measures of... Center Median Mean Mode Midrange Spread St Dev Range IQR Variance Example original data set {2,3,4} 2(data) 2(data) +3 8

9 9

10 10

11 Apply the "short-cut" transformations to the measures of Enter the following data into list L L 1 L 1 +3 L 1-5 2L 1 3L 1 2L L

12 12

13 13

14 = a + bx Measures of Center are affected by a and b. Measures of Spread are only affect by b. mean = 2.7 miles median = 1.54 miles If 1 mile = meters convert all statistics to meters 14

15 for one month. mean = median = standard deviation = by using the formula 15

16 16

17 17

18 18

19 A uniform density curve Use the areas under the density curve to answer the following questions. 19

20 2.11 A uniform density curve, II 20

21 Because this is a SYMMETRIC uniform density curve mean = median And its' location is in the center of the density curve x = 1.5 mile You could also solve for b in the equation b(1/3) = 0.5 Sketch density curves that might describe the distributions with the following shapes. b) Single peak and skewed to the left. 21

22 OTL C2#4 page 101: 17, 18 page 102: 19, 20, 21, 22, 23, 24, 26 Standard Deviation WS (be sure to do the back) FINISH Reading and Notes Chapter 2 Section 2 page 103 to 127 NOTES QUIZ TOMORROW!!! S x QUIZ TOMORROW!!! 22