Question 208297: Over the last several years, the use of cell phones has increased dramatically. According to a recent poll, the mean talking time per month for cell phones was 372 minutes for men and 275 minutes for women, while the mean talking time per month for traditional home phones was 334 minutes for men and 510 minutes for women.
Suppose that the poll was based on a sample of 100 men and 100 women, and that the standard deviation of talking time per month for cell phones was 120 minutes for men and 100 minutes for women, while the standard deviation of talking time per month for home phones was 110 minutes for men and 150 minutes for women. At the .05 level of significance, is there evidence of a difference in the variability of monthly talking time on cell phones for men and women?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! An independent testing agency has been contracted to determine whether there is any difference in gasoline mileage output of two different gasolines used in the same model automobile. The first gasoline was tested on 200 cars and produced a sample average of 18.5 miles per gallon with a standard deviation of 4.6 miles per gallon. The second was tested on a sample of 100 cars and produced a sample average of 19.34 miles per gallon with a standard deviation of 5.2 miles per gallon. At the .05 level of significance, is there evidence of a difference in performance of the two gasoline’s?
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Ho: u(1st)-u(2nd) = 0
Ha: u(1st)-u(2nd) is not 0
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I ran a 2 sample T-test and got the following:
test statistic: t = -1.37
p-value: 0.1726
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Conclusion: Since the p-value is greater than 5%,
Fail to reject Ho.
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This test provides no evidence of a difference in performance
of the two gasolines.
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Cheers,
Stan H.
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