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):

56.556.152.765.759.064.770.164.753.578.2

Assume that the population ofxvalues has an approximately normal distribution.

(a)

Use a calculator with mean and sample standard deviation keys to find the sample mean percentagexand the sample standard deviations. (Round your answers to four decimal places.)

x=%s=%

(b)

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

lower limit%upper limit%