A The method of tree ring dating gave the following years AD

A. The method of tree ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution.

1201 1264 1201 1264 1268 1316 1275 1317 1275

Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviation s. (Round your answers to the nearest whole number.)

x =___________ A.D.

s =____________ yr

(b) Find a 90% confidence interval for the mean of all tree ring dates from this archaeological site. (Round your answers to the nearest whole number.)

lower limit __________A.D.

upper limit__________ A.D.

B. How much do wild mountain lions weigh? Adult wild mountain lions (18 months or older) captured and released for the first time in the San Andres Mountains gave the following weights (pounds): 67 105 133 123 60 64

Assume that the population of x values has an approximately normal distribution. Use a calculator with mean and sample standard deviation keys to find the sample mean weight x and sample standard deviation s. (Round your answers to one decimal place.)

x =_______ lb

s =________ lb

Find a 75% confidence interval for the population average weight of all adult mountain lions in the specified region. (Round your answers to one decimal place.)

lower limit______ lb

upper limit_______ lb

C. What percentage of hospitals provide at least some charity care? Based on a random sample of hospital reports from eastern states, the following information is obtained (units in percentage of hospitals providing at least some charity care): 56.5 56.1 52.6 65.7 59.0 64.7 70.1 64.7 53.5 78.2

Assume that the population of x values has an approximately normal distribution. Use a calculator with mean and sample standard deviation keys to find the sample mean percentage x and the sample standard deviation s. (Round your answers to one decimal place.)

x =________ %

s = __________%

Find a 90% confidence interval for the population average of the percentage of hospitals providing at least some charity care. (Round your answers to one decimal place.)

lower limit ______%

upper limit ________%

Solution