MATH 221 Week 7 Quiz Statistics for Decision Making.

MATH 221 Week 7 Quiz: Statistics for
Decision-Making




(CO 4) From a random sample of 55 businesses, it is found that the mean time that employees
spend on personal issues each week is 5.8 hours with a standard deviation of 0.35 hours. What is
the 95% confidence interval for the amount of time spent on personal issues?

(5.72, 5.88)
Correct!

(5.71, 5.89)

(5.74, 5.90)

(5.73, 5.87)

See text page 301


Question 2
pts
(CO 4)If a confidence interval is given from 8.50 to 10.25 and the mean is known to be 9.375,
what is the margin of error?

0.438
Correct!

0.875

, 1.750

8.500

See text page 301


Question 3
pts
(CO 4) Which of the following is most likely to lead to a small margin of error?
Correct!

large sample size

small standard deviation

large maximum error

small mean

See text page 301


Question 4
pts
(CO 4) From a random sample of 41 teens, it is found that on average they spend 31.8 hours each
week online with a population standard deviation of 3.65 hours. What is the 90% confidence
interval for the amount of time they spend online each week?

(24.50, 39.10)

(29.99, 33.61)
Correct Answer

(30.86, 32.74)
You Answered

(28.15, 35.45)

See text page 301