QUESTION 1 Let x be a random variable representing the monthly cost of joining a health...

QUESTION 1

Let x be a random variable representing the monthly cost of joining a health club. We may assume that x has a normal distribution and that the population standard deviation is $5.20. A fitness magazine advertises that the mean monthly cost of joining a health club is $35. You work for a consumer advocacy group and are asked to test this claim. You find that a random sample of 40 health club monthly costs has a mean of $37.30. If you assume that the population mean is $35, find the P-value corresponding to the hypothesis that the average monthly cost is greater than $35 (i.e. right-tail test)

A.
0.037

B.
0.025

C.
0.012

D.
0.002

QUESTION 2

Let x be a random variable that represents the annual salary of an elementary school teacher. The mean annual salary is reported to be $50,590. Assume the standard deviation is $1800. If a random sample of 50 elementary school teachers is selected, what is the probability that the sample mean is less than $50,000?

A.
0.0102

B.
0.0312

C.
0.373

D.
0.312

QUESTION 3

A computer repair service found that a random sample of 45 repair costs had a mean cost of $659. Assume that the population standard deviation is $125. Calculate the margin of error, E, for a 95% confidence interval for the population mean µ.

A.
48.07

B.
34.92

C.
30.55

D.
36.52

QUESTION 4

Let x be a random variable that represents the length of an Atlantic croaker fish. If x is normally distributed with a mean of 10 inches and a standard deviation of 2 inches, find the length of Croaker fish at the bottom of the top 15%.

A.
7.927 inches

B.
8.234 inches

C.
11.546 inches

D.
12.073 inches

QUESTION 5

A computer repair service found that a random sample of 45 repair costs had a mean cost of $659. Assume that the population standard deviation is $125. Find the 95% confidence interval for the population mean repair cost µ of all computers.

A.
(612.5 , 705.5)

B.
(627.5 , 690.5)

C.
(622.5 , 695.5)

D.
(623.5 , 694.5)

QUESTION 6

Let x be a random variable that represents the length of an Atlantic croaker fish. If x is normally distributed with a mean of 10 inches and a standard deviation of 2 inches, find the probability that length of the fish is between 8.4 inches and 10.2 inches.

A.
0.672

B.
0.328

C.
0.788

D.
0.212

QUESTION 7

Let x be a random variable representing the monthly cost of joining a health club. We may assume that x has a normal distribution and that the population standard deviation is $5.20. A fitness magazine advertises that the mean monthly cost of joining a health club is $35. You work for a consumer advocacy group and are asked to test this claim. You find that a random sample of 40 health club monthly costs has a mean of $37.30. If you assume that the population mean is $35, find the standardized sample test statistic.

A.
3.157

B.
2.149

C.
2.797

D.
1.543

Solutions

Expert Solution

orchestra answered 1 year ago

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Subjects

	A.	(612.5 , 705.5)
	B.	(627.5 , 690.5)
	C.	(622.5 , 695.5)
	D.	(623.5 , 694.5)

	A.	0.037
	B.	0.025
	C.	0.012
	D.	0.002

	A.	0.0102
	B.	0.0312
	C.	0.373
	D.	0.312

	A.	48.07
	B.	34.92
	C.	30.55
	D.	36.52

	A.	7.927 inches
	B.	8.234 inches
	C.	11.546 inches
	D.	12.073 inches