Please answer the following questions.

1. A random sample of the number of farms (in thousands) in various states follows. Estimate the mean number of farms per state with 93% confidence. Assume =31. Use a graphing calculator and round the answers to one decimal place. Assume the population is normally distributed.

50	78	54	33	64	4	8	52	9	80
40	90	3	57	4	6	79	29	48	16
68	7	15	21	49

2. A random sample of the number of farms (in thousands) in various states follows. Estimate the mean number of farms per state with 99% confidence. Assume =31. Round intermediate and final answers to one decimal place. Assume the population is normally distributed.

79	44	49	3	90	80	9	57	8	4	64
33	54	95	47	50	40	109

3. For a random sample of 60 overweight men, the mean of the number of pounds that they were overweight was 31. The standard deviation of the population is 3.8 pounds. Use a graphing calculator and round the final answers to one decimal place.

• The best point estimate of the mean is ___ pounds.

4. For a certain group of individuals, the average heart rate is 73 beats per minute. Assume the variable is normally distributed and the standard deviation is 2 beats per minute. If a subject is selected at random, find the probability that the person has the following heart rate. Use a graphing calculator. Round the answers to four decimal places.

• Higher than 72 beats.

5. Americans drank an average of 23.2 gallons of bottled water per capita in 2004. If the standard deviation is 2.7 gallons and the variable is normally distributed, find the following probabilities. Use a graphing calculator and round the answers to four decimal places.

• Between 18 and 29 gallons of bottled water.

6. A sociologist found that in a sample of 57 retired men, the average number of jobs they had during their lifetimes was 7.3. The population standard deviation is 2.1. Use a graphing calculator and round the answers to one decimal place.

• The best point estimate of the mean is___.

7. Noise levels at various area urban hospitals were measured in decibels. The mean noise level in 163 ward areas was 59.9 decibels, and the population standard deviation is 4.7. Find the 90% confidence interval of the true mean. Round your answers to at least one decimal place.

8. A pizza shop owner wishes to find the 90% confidence interval of the true mean cost of a large plain pizza. How large should the sample be if she wishes to be accurate to within $0.16? A previous study showed that the standard deviation of the price was $0.23. Round your final answer up to the next whole number.

• The owner needs at least a sample of ___ pizzas.

9. If the variance of the water temperature in a lake is 25 , how many days should the researcher select to measure the temperature to estimate the true mean within 2 with 90% confidence? Round the intermediate calculations to two decimal places and round up your final answer to the next whole number.

• The researcher needs a sample of at least ___ days.