at All 77% 2:37 PM

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My Notes + Ask Your Teacher

What are the big corporations doing with their

wealth? One way to answer this question is to

examine profits as percentage of assets. A random

sample of 50 Fortune 500 companies gave the

following information. Estimate the sample mean,

sample variance, and sample standard deviation

for profit as percentage of assets. (Round your

answers to three decimal places.)

Profit as percentage of assets 8.6-12.5

15

12.6-16.5

16.6-20.5

20.6-24.5

24.6-28.5

Number of companies

x 14.803

2 23.39

8 4.84

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12. + 2/3 points Previous Answers

My Notes + Ask Your Teacher

Alexander Borbely is a professor at the University

of Zurich Medical School, where he is director of

the sleep laboratory. The histogram in the figure

below is based on information from his book

Secrets of Sleep. The histogram displays hours of

sleep per day for a random sample of 200

subjects. Estimate the mean hours of sleep,

standard deviation of hours of sleep and

coefficient of variation. (Enter x to 1 decimal place,

s and CV to 2 decimal places.)

Frequency

8

80

TOL

60

50

40

30

22

20

14

10

3.5

45

5.5

95 105

Hours of sleep

x 7.9

$ 1.05

CV 13.28

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