stats week 6

Homework 4

  1. Prior to being hired, the ten salespersons for a computer store were given a standard sales aptitude test. For each individual, the score achieved on the aptitude test and the number of computer systems sold during the first 3 months of their employments are shown here (20 points)


Name

Score on aptitude test

Units sold in 3 months

Susan

Michael

Smith

Randy

Todd

Rick

Wilson

Lily

Tom

Molly

23

55

47

88

27

42

58

81

32

70

50

41

15

63

55

14

57

66

29

67


(A). Determine the regression line (dependent variable: Unit sold in 3 month, independent variable: Score on aptitude test) and interpret the slope and discuss its significance.

(B). Predict, for a new employee who scores 60 on the sales aptitude test, the number of units the new employee will see in her first 3 months with the company.

  1. The following data describe U.S. motor vehicle travel and fuel consumption from 2002 through 2007. The data represent billions of gallons consumed and billions of miles traveled, respectively.(20 points)


Year

Fuel Consumed

Mile Traveled

2002

2003

2004

2005

2006

2007

178.7

171.0

174.5

178.8

179.9

185.9

3111

3256

3378

3412

3512

3666


  1. Determine the regression line for predicting fuel consumption on the basis of driving mile. Note that the dependent variable should be fuel consumed and the independent variable should be mile traveled.

  2. Use the 0.05 level in testing whether the slope of driving mile could be zero, and interpret the slope