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 55.5 53.5 66.5 59.0 64.7 70.1 64.7 53.5 78.2

A button hyperlink to the SALT program that reads: Use SALT.

Assume that the population of x values has an approximately normal distribution.

(a)

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 four decimal places.)

x =

%

s =

%

(b)

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

%