Question

                     

An instructor wants to use a pre-test to help predict final grades in his class. She finds the regression line to be:

predicted final grade = 0.49 + 0.56 x pre-test score.

Joe gets a 75% on the pre-test. Below is the Minitab output for this example. Please indicate the prediction interval for a person with a score of 75 on the pre-test.

Predicted Values for New Observations

New Obs     Fit         SE Fit            95% CI                  95% PI

1                 0.75        0.045             (0.65, 0.84)            (0.81, 0.95)

Answer 1

The 95% prediction interval for a person with a score of 75 on the pre-test is (0.81, 0.95) .