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1. A basketball player makes 85% of the free throws she tries. Assume this percentage holds true for future attempts. a. Find the mean and standard deviation of the number of baskets she will make out of eight free throws. b. Find the probability that in the next eight tries, the number of free throws she will make is exactly 8.

2. According to a Center for Disease Control and Prevention estimate, 70% of adult cigarette smokers in the United States want to quit smoking (Statistical Bulletin, April-June 1996). Assume that this result holds true for the current population of all adult smokers. a. Find the mean and standard deviation of the proportion in a random sample of 120 smokers who want to quit smoking. b. Used the Normal approximation to find the probability that the proportion of smokers who want to quit in a random sample of 120 will be more than 0.72.

3. The time that college students spend studying per week has a distribution with a mean of 8.4 hours and a standard deviation of 2.7 hours. Find the probability that the mean time spent studying per week for a random sample of 45 students would be less than 8 hours.

4.A. The U.S. Travel Industry estimated that Americans planned to spend an average of 4.8 nights away on vacations in 1995 (U.S. News & World Report, June 12, 1995). Suppose that this mean was based on a random sample of 500 Americans who planned vacations and that the population standard deviation was 1.5 nights. a. Use a 99% confidence interval to estimate the mean length of vacations Americans planned in 1995. b. Test the hypothesis H0: m=5 days against the hypothesis Ha: m<5 days. Use a=0.05.

4.B. A department store manager wants to estimate at a 90% confidence level the mean amount spent by all customers at this store. From an earlier study, the manager knows that the standard deviation of amounts spent by customers at this store is $27. What should she choose so that the estimate is within $3 of the population mean?

5. According to the U.S. Bureau of the Census data for 1993, students required an average of 6.29 years beyond high school to obtain a bachelor's degree. A recently taken sample of 27 newly awarded bachelor's degree holders showed that it took them a mean of 6.90 years to obtain the degree after finishing high school, with a sample standard deviation of 1.1 years. Using the 1% significance level, can you conclude that the mean time required for all students to obtain a bachelor's degree is currently greater than 6.29 years? (In answering this question: State the null and alternative hypothesis Find the P-Value and report your conclusions.)