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question 9 The following table shows the weights (in pounds) and the number of h

ID: 3155083 • Letter: Q

Question

question 9

The following table shows the weights (in pounds) and the number of hours slept in a day by a random sample of infants. Test the claim that

M 0. Use =0.10.1.

Then interpret the results in the context of the problem. If convenient, use technology to solve the problem.

Weight, x

8.1   

10.2   

9.9

7.2

6.8

11.3

10.9

15.1

Hours slept, y

14.9

14.6

14.1

14.2

13.8

13.2

13.9

12.4

Identify the null and alternative hypotheses.

C.

H0: M =0

Ha M0

Calculate the test statistic.

round to three decimal places as needed.

t =?????

Weight, x

8.1   

10.2   

9.9

7.2

6.8

11.3

10.9

15.1

Hours slept, y

14.9

14.6

14.1

14.2

13.8

13.2

13.9

12.4

Explanation / Answer

Compute Pearson correlation coefficient, r=-0.734 (using technology). Virtually any technology can find the value of r, here Minitab is used. For which enter the given data>Go to stat> Basic statistics>Correlation>enter C1 and C2 and click OK.

Compute t test statistic.

t=r/sqrt[1-r^2/n-2]

=-0.734/sqrt[1-0.734^2/8-2]

=-2.65

The p value at df=6 (n-2) is 0.0380.

The p value is less than alpha=0.1. Reject null hypothesis to conclude that weight and hours of sleep are negatively linearly correlated.