4. A stock index fund invests in a very large number of different stocks, so the return you get from it is roughly the average return for the stocks in the index.
a. Which of these two choices would give you a better chance of tripling your money within a month: investing all your money in the index fund, or investing all your money in a few randomly chosen stocks that make up the index?
b. Which of these two choices would give you a better chance o flossing almost all of your money within a month: investing all your money in the index fund, or investing all your money in a few randomly chosen stocks that make up the index?
22. Twenty five independent polls of one thousand random people each are taken during the course of an extremely close election campaign. People in the poll are asked which of the two candidates they favor and the percentage who favor the incumbent candidate is computed for each poll.
a. Estimate the standard error and the margin of error for each of these polls. Justify your answer and briefly explain the differences between them.
b. How large a poll sample would be required if a margin of error of only 10% was desired?
c. One of the other candidate’s approval ratings averaged around 48% over all the twenty five polls. If you computed the standard deviation of the list of all twenty five poll percentages for this candidate, approximately what number would you expect to get? Explain.
17. Reports from a new system set up to monitor Internet use by company employees indicate that 145 out of a random sample of 1100 employees at a corporation accessed internet sites that were clearly not related to their jobs over the last week. On average, employees who accessed non job related sites spent 4.8 hours per week at such sites with a standard deviation of 2.1 hours
a. Give a 95% confidence interval for the percentage of employees at the corporation who access non job related sites.
b. Briefly explain in one short sentence how to interpret...