Suppose that a regional express delivery service company wants to estimate the cost of shipping a package (Y) as a function of cargo type, where cargo type includes the following possibilities: fragile, semi fragile, and durable. Costs for 15 randomly chosen packages of approximately the same weight and same distance shipped, but of different cargo types, are provided in the file P10_28.xlsx.
a. Estimate an appropriate multiple regression equation to predict the cost of shipping a given package.
b. Interpret the ANOVA table for this model. In particular, do the explanatory variables included in your equation in part a provide at least some power in explaining the variation in shipping costs? Report a p-value for this hypothesis test.