stats week 6

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)

(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.

2. 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)

(A) 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.

(B) Use the 0.05 level in testing whether the slope of driving mile could be zero, and interpret the slope