Question

During its manufacture, a product is subjected to four different tests in sequential order. An efficiency expert claims that the fourth (and last) test is unnecessay since its results can be predicted based on the first three tests. To test this claim, multiple regression will be used to model Test score), as a function of Test score xyl Test 2 score and Test score (13) (Note: All test scores range from 200 to 800, with higher scores indicative of a higher quality product] Consider the model Ely) =B1 + Bixi + 2x2 + 3x3 The first-order model was fit to the data for each of 12 units sampled from the production line. The results we summarized in the printout SOURCE DE SS MS F VALLE PROB> 15.16 os MODEL ERROR TOTAL 3 8 12 151412 22231 173645 50072 279 ROOT MSE 52.72 0.872 R-SQUARE ADJ R SQ DEP MEAN 6458 0824 PARAMETER ESTIMATE STANDARD ERROR TFORD PARAMETER - VARIABLE PROB>T 404 INTERCEPT 11.98 500 0.15 XITESTI 02745 01111 0.000 XATEST2) 03762 0.0966 3.82 XXTEST3 0.265 060 0.00 Suppose the 95% confidence interval for 3 is (1547). Which of the following statements is incorrect? We are 95% confident that the Test3 is a useful linear predictor of Test4 score, holding Test and Test2 fixed We are 95% confident that the estimated slope for the Test Test3 line falls between 15 and 47 holding Test and Test2 fixed At a = 05, there is insufficient evidence to reject Hop in favor of He 30 We are confident that the increase in Test score for every 1-point increase in Test3 score falls between 15 and 47 holding Test and Test2 fixed

Answer 1

Ans: Option 4

We are 95% confident that the increase in Test4 score for every 1-point increase in Test3 score falls between 15 and 47, holding Testi and Test2 fixed