Question 11.41

For Exercise 11.33, see page 550; for 11.34 and 11.35, see page 554; for 11.36 and 11.37, see page 555; for 11.38, see page 558; for 11.39, see page 559; and for 11.40 and 11.41, see pages 560–561.

Question 11.41

CASE 11.2

11.41 Is Opening helpful when Budget and Theaters are available?

We saw that Budget and Theaters are not useful in a model that contains the opening-weekend revenue. Now, let’s examine the other version of this question. Does Opening help explain USRevenue in a model that contains Budget and Theaters? Run the models with all three predictors and with only Budget and Theaters. Compare the values of $R^{2}$ . Perform the $F$ test and give its degrees of freedom and $P$ -value. Carefully state a conclusion about the usefulness of the predictor Opening when Budget and Theaters are available. Also compare this $F$ -test and $P$ -value with the $t$ test for the coefficient of Opening in Example 11.13.

11.41

The $R^{2}$ value for all three predictors is 0.7156. The $R^{2}$ value for just Budget and Theaters is 0.4355. $F = 38.42, d f = 1$ . Opening does contribute significantly to explaining U.S. box office revenue when Budget and Theaters are already in the model. The conclusion is the same as the $t$ test.

movies