Even though the budget for a movie may be close to $300 million, worldwide distribution can provide a huge net income for a studio. The following table includes a sample of movies, the budget (in...

Even though the budget for a movie may be close to $300 million, worldwide distribution can provide a huge net income for a studio. The following table includes a sample of movies, the budget (in dollars) for each, and the U.S. gross income (in dollars) for each.

a. Find a 95% confidence interval for the population variance in gross income.

b. Compute the ratio of U.S. revenue to budget (ratio 5 gross/budget) for each movie. Find a 95% confidence  interval for the population variance in ratio of revenue to budget.

c. If the variance in the ratio is greater than 1, it is considered risky to invest in a new film. Is there any evidence to suggest investing in a new movie is risky? Justify your answer.