Develop a multiple regression model containing all four independent variables. Show clearly the regression coefficients. Write a short report discussing the model. In your report make sure you cover the following issues:
a. How much of the total variation in book sales can be explained by these four independent variables? Would you conclude that the model is significant at the 0.05 level?
b. Develop a 95% confidence interval for each regression coefficient and interpret these confidence intervals.
c. Which of the independent variables can you conclude to be significant in explaining the variation in book sales? Test using α = 0.05.
d. How much of the variation in the dependent variable is explained by the independent variables? Is the model statistically significant at the α = 0.01 level? Discuss.
e. How much, if at all, does adding one more page to the book impact the sales volume of the book? Develop and interpret a 95% confidence interval estimate to answer this question.
f. Perform the appropriate analysis to determine the aptness of this regression model. Discuss your results and conclusions.
A publishing company in New York is attempting to develop a model that it can use to help predict textbook sales for books it is considering for future publication. The marketing department has collected data on several variables from a random sample of 15 books. These data are given in the file Textbooks