. 2. Michael London (of Sideways fame ) declared in The Hollywood Reporter, "The studio business historically returns around 12 percent a year." Griffith knew any investor would want justification for such a statement. a. Calculate the U.S. return on investment (ROI) (simply defined as the difference of total U.S. box-office gross and budget divided by budget, ignoring any form of discounting) for each movie in the data set. b. Provide a 95 percent confidence interval for the mean U.S. ROI of movies. C. Show that the mean U.S. ROI is significantly larger than the 12 percent London cited