(a) A small P-value for the ANOVA F test implies that all explanatory variables are significantly different from zero.

(b) R² is the proportion of variation explained by the collection of explanatory variables. It can obtained by squaring the correlations between y and each x_i and summing them up.

(c) In a multiple regression with a sample size of 45 and six explanatory variables, the test statistic for the null hypothesis H₀: b₂ = 0 is a t statistic that follows the t(38) distribution when the null hypothesis is true.