Problem 14 in Chapter 15 described a study examining the effectiveness of a 7-Minute Screen test for Alzheimer's disease. The study evaluated the relationship between scores from the 7-Minute Screen and scores for the same patients from a set of cognitive exams that are typically used to test for Alzheimer's disease. For a sample of n = 9 patients, the scores for the 7-Minute Screen averaged M = 7 with SS = 92. The cognitive test scores averaged M = 17 with SS = 236. For these data, SP = 127.
a. Find the regression equation for predicting the cognitive scores from the 7-Minute Screen score.
b. What percentage of variance in the cognitive scores is accounted for by the regression equation?
c. Does the regression equation account for a significant portion of the variance in the cognitive scores?
Use α = .05 to evaluate the F-ratio.