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:...

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, semifragile, 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 P16_18.xlsx.


a. Formulate an appropriate multiple regression model to predict the cost of shipping a given package.


b. Estimate the formulated model using the given sample data, and interpret the estimated regression coefficients.


c. According to the estimated regression model, which cargo type is the most costly to ship? Which cargo type is the least costly to ship?


d. How well does the estimated model fit the given sample data? How might the model be improved?


e. Given the estimated regression model, predict the cost of shipping a package with semifragile cargo.