Question

Data on the numbers of hospital admissions resulting from motor vehicle crashes are given below for Fridays on the 6th of a month and Fridays on the following 13th of the same month. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Construct a​ 95% confidence interval estimate of the mean of the population of differences between hospital admissions. Use the confidence interval to test the claim that when the 13th day of a month falls on a​ Friday, the numbers of hospital admissions from motor vehicle crashes are not affected.

Friday the 6th

1010

55

99

88

55

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Friday the 13 thFriday the 13th

1414

1010

1414

1212

1313

In this​ example,

mu Subscript dμd

is the mean value of the differences d for the population of all pairs of​ data, where each individual difference d is defined as the number of hospital admissions on Friday the 6th minus the number of hospital admissions on Friday the 13th. Find the​ 95% confidence interval.

nothing less than<mu Subscript dμdless than<nothing

​(Round to two decimal places as​ needed.)

Based on the confidence​ interval, can one reject the claim that when the 13th day of a month falls on a​ Friday, the numbers of hospital admissions from motor vehicle crashes are not​ affected?

A.

YesYes​,

because the confidence interval

does not includedoes not include

zero.

B.

YesYes​,

because the confidence interval

includesincludes

zero.

C.

NoNo​,

because the confidence interval

includesincludes

zero.

D.

NoNo​,

because the confidence interval

does not includedoes not include

zero.

Answer 1

95% confidence interval =-7.24 < μ < -3.16

Yes​, because the confidence interval does not include zero,.