Concept explainers
For Exercises 5 through 16, perform each of the following steps.
a. State the hypotheses and identify the claim.
b. Find the critical value(s).
c. Compute the test value.
d. Make the decision.
e. Summarize the results.
7. Commuting Times The U.S. Census Bureau reports that the average commuting time for citizens of both Baltimore, Maryland, and Miami, Florida, is approximately 29 minutes. To see if their commuting times appear to be any different in the winter, random samples of 40 drivers were surveyed in each city and the average commuting time for the month of January was calculated for both cities. The results are shown. At the 0.05 level of significance, can it be concluded that the commuting times are different in the winter?
Miami | Baltimore | |
40 | 40 | |
Sample mean | 28.5 min | 35.2 min |
Population standard deviation | 7.2 min | 9.1 min |
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Elementary Statistics: A Step By Step Approach
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