The Internet Movie Database (www.imdb.com) monitors the gross revenues of all major motion pictures. The table below gives both the domestic (United States and Canada) and international gross revenues for a sample of 20 popular movies. The data are saved in the IMDB file.

a. Write a first-order model for international gross revenues y as a function of domestic gross revenues x.

b. Write a second-order model for international gross revenues y as a function of domestic gross revenues x.

c. Construct a scatterplot of these data. Which of the models appears to be a better choice for explaining variation in international gross revenues?

d. Fit the model of part b to the data and investigate its usefulness. Is there evidence of a curvilinear relationship between international and domestic gross revenues? Test, using α = .05.

e. On the basis of your analysis in part d, which of the two models better explains the variation in international gross revenues?