A financial analyst believes that the best way to predict a firm's returns is by using the firm's price-to-earnings ratio

(P/E) and its price-to sales ratio (P/S) as explanatory variables.

He estimates the following regression, using 30 large firms:

A colleague suggests that he can improve on his prediction if he also includes the P/E-to-growth ratio (PEG) and the dividend yield (DIV). He re-estimates the model by including these explanatory variables and obtains At the 5% significance level, is the colleague's claim substantiated by the data? Explain.