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):

57.5 56.1 52.7 66.1 59.0 64.7 70.1 64.7 53.5 78.2

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 one decimal place.)

x=62.2%

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______%