6.6. Refer to Brand preference Problem 6.5. Assume that regression model (6.1) with independent normal error terms is appropriate. a. Test whether there is a regression relation, using a = .01. State the alternatives, decision rule, and conclusion. What does your test imply about B₁ and B₂? Chapter 6 Multiple Regression I 249 b. What is the P-value of the test in part (a)? c. Estimate B1 and B2 jointly by the Bonferroni procedure, using a 99 percent family confidence coefficient. Interpret your results. 6.5. Brand preference. In a small-scale experimental study of the relation between degree of brand liking (Y) and moisture content (X₁) and sweetness (X2) of the product, the following results were obtained from the experiment based on a completely randomized design (data are coded): i: 1 2 3 ... Xi1: 4 4 4 Xi2: 2 4 2 Y;: 64 73 61 1045 15 16 10 10 2 4 95 94 100 64.0 4.0 2.0 73.0 4.0 4.0 61.0 4.0 2.0 76.0 4.0 4.0 72.0 6.0 2.0 80.0 6.0 4.0 71.0 6.0 2.0 83.0 6.0 4.0 83.0 8.0 2.0 89.0 8.0 4.0 86.0 8.0 2.0 93.0 8.0 4.0 88.0 10.0 2.0 95.0 10.0 4.0 94.0 10.0 2.0 100.0 10.0 4.0