Ten years ago 53% of American families owned stocks or stock funds. Sample data collected by the Investment Company Institute indicate that the percentage is now 46%. (a) Formulate a hypothesis test that can be used to determine if the proportion of American families own stocks or stock funds is smaller than 10 years ago. (b) Assume the Investment Company Institute sampled 300 American families to es- timate that the percent owning stocks or stock funds was 46%. How many Amer- ican families in the survey own stocks or stock funds? (c) Compute the 95% confidence interval for the proportion of American families own stocks or stock funds. (d) Using confidence interval in part (c), would you conclude that the