4 What percentage of hospitals provide at least some charity

4. 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):

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 one decimal place.)

(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.)

5. The price of a share of stock divided by the company\'s estimated future earnings per share is called the P/E ratio. High P/E ratios usually indicate \"growth\" stocks, or maybe stocks that are simply overpriced. Low P/E ratios indicate \"value\" stocks or bargain stocks. A random sample of 51 of the largest companies in the United States gave the following P/E ratios

Solution

(4)(a) mean=62.3

s=8.1

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(b)

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(5)(a) mean=25.2

s=15.5

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(b)

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(c)

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(d)

We can say Bank One is below average, AT&T Wireless is above average, and Disney is below average.

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(e)Yes. According to the central limit theorem, when n ? 30, the x distribution is approximately normal.