The following model was used to relate E(y) to a single qualitative variable with four levels:
E(y) = β0 + β1x1 + β2x2 + β3x3
where

This model was fit to n = 30 data points, and the following result was obtained:
= 10.2 - 4x1 + 12x2 + 2x3
a. Use the least squares prediction equation to find the estimate of E(y) for each level of the qualitative independent variable.
b. Specify the null and alternative hypotheses you would use to test whether E(y) is the same for all four levels of the independent variable.

Transcribed Image Text:

ぬ-Gif level 3 l if level 3 x,-{1 0if not ={1 if level 2 o if not