Question

Fill in the blank. Speed Car Rental company found that the tire lifetime for their vehicles has a mean of 46,177.02 miles and standard deviation of 5,585.8 miles. In a sample of 68 tires tested, there is a 48% chance that the average tire lifetime is less than ________ miles.

1)

46,457.17

2)

46,210.99

3)

46,143.05

4)	There is not enough information to determine this.

5)

45,896.87

The Student Recreation Center wanted to determine what sort of physical activity was preferred by students. In a survey of 90 students, 67 indicated that they preferred outdoor exercise over exercising in a gym. When estimating the proportion of all students at the university who prefer outdoor exercise with 95% confidence, what is the margin of error?

1)

0.0095

2)

0.0754

3)

0.0901

4)

0.0460

5)

0.0041

You are interested in getting an investment portfolio started with any extra money you make from your part time job while also going to school. While flipping through the latest edition of Money magazine, you read an article that of a survey of magazine subscribers, 200 were randomly selected and analyzed. A 95% confidence interval was constructed for the proportion of all subscribers who made money in the previous year in their investments, which was ( 0.6954 , 0.8146 ). What is the correct interpretation of this confidence interval?

1)	We are 95% confident that the proportion of all Money magazine subscribers sampled that made money in the previous year from their investments is between 0.6954 and 0.8146.

2)	We are certain that 95% of subscribers made between 0.6954 and 0.8146.

3)	We are 95% confident that the proportion of all Money magazine subscribers that made money in the previous year from their investments is between 0.6954 and 0.8146.

4)	We are 95% confident that of the 200 respondents, between 0.6954 and 0.8146 of them made more than they lost.

5)	We cannot determine the proper interpretation of this interval.

Answer 1