1. Explain why a 95% confidence interval estimate for the mean value of y at a particular x is narrower than a 95% confidence interval for an individual y value at the same value of x.

2. You are given the following information from fitting a multiple regression with three variables to 30 sample data points:

????1=1.3

????2=10.0

????3=25.2

????????1=0.3

????????2=2.0

????????3=15.0

Test the following Hypotheses, Use alpha = .05:

1. a) Beta1=0

b) Beta2=0

c) Beta3=0