Part B **5. (Continuation of GPA). (a) Obtain a 90% interval estimate for the mean freshman GPA for students whose ACT test score is 24. Interpret it in a sentence. (b) Mabel obtained a 25 on the ACT test. Predict her freshman GPA using a 98% prediction interval. Interpret it in a sentence. Is your interval wider than the one in part (a)? Should it be? (c) Determine the boundary values of the 90% confidence band for the regression line when xh = 25. Is your confidence band wider at this point than the interval in part (a)? Should it be?