1. Develop the correlation matrix showing the correlation between all possible pairs of variables. Test statistically to determine which independent variables are significantly correlated with the dependent variable, book sales. Use a significance level of 0.05.
2. 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 a = 0.05.
d. How much of the variation in the dependent variable is explained by the independent variable? Is the model statistically significant at the a = 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.