The accompanying data file contains 20 observations on the response variable y along with the predictor variables x₁ and x₂.

a. Estimate a regression model with the predictor variables x₁ and x₂, and then extend it to also include the interaction variable x₁x₂.What is the estimated regression coefficient for the predictor variable x₁ and x₂ in both models?

Note: Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.

X1 X2

Model 1(no interaction) ________ _________

Model 2 (interaction) ________ _________

b. Which is the preferred model for making predictions?

a. Model 1

b. Model 2

c. Use the preferred model to predict y.

Note: Round coefficient estimates to at least 4 decimal places and final answers to 2 decimal places.

Predictor Variable Predicted y

x1 = 30, x1 = 10 ________

x1 = 30, x2 = 20 ________

y	x1	x2
37	22	33
51	32	35
57	30	25
42	28	22
28	21	17
87	34	9
64	27	33
52	30	19
45	28	34
56	28	5
31	21	32
34	21	12
50	28	16
84	34	13
44	23	29
54	28	15
31	22	13
50	29	22
66	26	14
72	38	21