1. Suppose you fit the first-order multiple regression model

yi=0+1xi,1+2xi,2+i(1)

ton= 25data points and obtain the prediction equation

y=6.4+3.1x+.92x(2)

i i,1i,2

The estimated standard deviations of the sampling distributions of1and2are 2.3 and 0.27, respec-

tively.

(a) TestH0:1=0againstHa:1>0. Use=.05.

(b) Find a 99% confidence interval for2. Interpret the coefficient.