Question 1
The data for
n = 37 points were subjected to a simple linear regression with the results:

and

a. | Test whether the two variables, x and y, are positively linearly related. Use α = .05. |
b. | Construct and interpret a 90% confidence interval for β1. |
Question 2
In a comprehensive road test on new car models, one variable measured is the time it takes a car to accelerate from 0 to 60 miles per hour. To model acceleration time, a regression analysis is conducted on a random sample of 129 new cars.
TIME60: | y = Elapsed time (in seconds) from 0 mph to 60 mph |
MAX: | x = Maximum speed attained (miles per hour) |
The simple linear model
E(
y) =
β0 +
β1x was fit to the data. Computer printouts for the analysis are given below:
NWEIGHTED LEAST SQUARES LINEAR REGRESSION OF TIME60



CASES INCLUDED 129 MISSING CASES 0
Fill in the blank: "At
α =.05, there is ________________ between maximum speed and acceleration time."
◦ insufficient evidence of a linear relationship
◦ insufficient evidence of a negative linear relationship
◦ sufficient evidence of a positive linear relationship
◦ sufficient evidence of a negative linear relationship