Consider the following data for a dependent variable y and two independent variables, x1 and x2.

x1 x2 y
30 12 94
47 10 108
25 17 112
51 16 178
40 5 94
51 19 175
74 7 170
36 12 117
59 13 142
76 16 211

The estimated regression equation for this data is

? = –18.4 + 2.01x1 + 4.74x2

Round your answers to three decimal places.

a. Develop a 95% confidence interval for the mean value of y when x1 = 45 and x2 = 15.

b. Develop a 95% prediction interval for y when x1 = 45 and x2 = 15.