Question

Classified ads in a newspaper offered for sale 15 used cars of the same make and model. The output of a regression analysis is given. Assume all conditions for regression have been satisfied. Create a​ 95% confidence interval for the slope of the regression line and explain what your interval means in context.

Coeff. SE ​t-Stat

​y-Int. 12204 563.07 21.674

Age -1029 83.34 -12.347

Find the​ 95% confidence interval for the slope.

The confidence interval is (___,___) ​(Round to two decimal places as​ needed.)

What does the​ 95% confidence interval mean in​ context?

A. It can be said with​ 95% confidence that next​ year, the price of each used car will have changed by an amount contained in the interval.

B. It can be said with​ 95% confidence that the interval contains the true rate at which the price of a used car changes in relation to its age.

C. The true rate at which the price of a used car changes in relation to its age is between the endpoints of the confidence interval​ 95% of the time.

Answer 1

Here

estimated slope = -1029

and standard error of slope = 83.34

and sample size n = 15

a 95% confidence interval for the slope is

Interpretation :

B. It can be said with​ 95% confidence that the interval contains the true rate at which the price of a used car changes in relation to its age.