Consider a linear regression model where y represents the response variable and x1 and x2 are the predictor variables. A regression model with x1, x2, and x1x2, where x1x2 is the interaction variable, is estimated as y y ^ = 123.12 + 8.11x1 1.53x2 0.12x1x2.

a-1. Compute y y ^ for x1 = 12 and x2 = 20. Note: Round your answer to 2 decimal places.

a-2. Compute y y ^ for x1 = 12 and x2 = 30. Note: Round your answer to 2 decimal places.

b-1. Compute y y ^ for x1 = 24 and x2 = 20. Note: Round your answer to 2 decimal places.

b-2. Compute y y ^ for x1 = 24 and x2 = 30. Note: Round your answer to 2 decimal places.