MATH 534 Week 5 Quiz

1. Question: In a hypothesis test, the test statistic computed from the sample data is considered extreme or significant if it is __________ 2. Question: A test of the hypotheses, H0: p = 0.18 and H1: p ≠ 0.18 is a _______________. 3. Question: An analyst tested the null hypothesis µ ≥ 30 against the alternative hypothesis that µ < 30. The analyst reported a p-value of 0.07. For what significance level of α will the null hypothesis would be rejected? 4. Question: The dean of a business school claims that the average starting salary of its graduates is more than 85 (in $000’s). It is known that the population standard deviation is 10 (in $000’s). Sample data on the starting salaries of 64 randomly selected recent graduates yielded a mean of 88 (in $000s). Which of the following sets of hypotheses is correct? 5. Question: The dean of a business school claims that the average starting salary of its graduates is more than 85 (in $000’s). It is known that the population standard deviation is 10 (in $000’s). Sample data on the starting salaries of 64 randomly selected recent graduates yielded a mean of 88(in $000s). What is the critical value for the rejection region if the level of significance is 5%? 6. Question: If the calculated test statistic falls in the rejection region, the statistical action is to ________. 7. Question: A researcher is testing a hypothesis of a single mean. The critical z value for α = .05 and a two-tailed test is +1.96. The observed z value from sample data is 2.85. The decision made by the researcher based on this information is to ________the null hypothesis. 8. Question: Use the information given and the eight-step approach to test the hypotheses. 9. Question: The weight of a USB flash drive is 30 grams and is normally distributed. Periodically, quality control inspectors at Dallas Flash Drives randomly select a sample of 17 USB flash drives. If the mean weight of the USB flash drives is too heavy or too light the machinery is shut down for adjustment; otherwise, the production process continues. The last sample showed a mean and standard deviation of 31.9 and 1.8 grams, respectively. Using α = 0.10, the appropriate decision is ____________. 10. Question: The executives of CareFree Insurance, Inc. feel that "a majority of our employees perceive a participatory management style at CareFree." A random sample of 200 CareFree employees is selected to test this hypothesis at the 0.05 level of significance. Ninety employees rate the management as participatory. The appropriate decision is ____________. 11. Question: Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of email messages sent by GFS employees are not business related. A random sample of 300 e-mail messages was selected to test this hypothesis at the 0.01 level of significance. Sixty of the messages were not business related. The appropriate decision is ___________. 12. Question: The customer help center in your company receives calls from customers who need help with some of the customized software solutions your company provides. Previous studies had indicated that 20% of customers who call the help center are Hispanics whose native language is Spanish and therefore would prefer to talk to a Spanishspeaking representative. This figure coincides with the national proportion, as shown by multiple larger polls. You want to test the hypothesis that 20% of the callers would prefer to talk to a Spanishspeaking representative. You conduct a statistical study with a sample of 35 calls and find out that 11 of the callers would prefer a Spanishspeaking representative. The significance level for this test is 0.01. The value of the test statistic obtained is: