Tests Of Significance Quiz 2 (18 MCQs)

Quiz Instructions

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1. What does it mean when a test is statistically significant?
2. What is the Power of a test?
3. The football coach thinks about half his players are skipping leg day in the gym. He follows 10 of his players around for a week, he found that 6 of them skipped leg day in the gym. Does this give evidence that over half of his students are skipping leg day?
4. An engineer designs an improved light bulb. The previous design had an average lifetime of 1200 hours. The new bulb had a lifetime of 1201 hours, using a sample of 2000 bulbs. Although the difference is quite small, the effect was statistically significant. The explanation is that
5. On August 8, 2009 broadcasters on the Fox TV "Game of the Week" noted that Yankees outfielder Nick Swisher hit 3 home runs at home and 15 on the road. He claimed that his performances indicate that Swisher has a greater ability to hit home runs at home than on the road. What is the null hypothesis?
6. A tire manufacturer claims that one particular type of tire will last at least 50, 000 miles. A group of angry customers does not believe this is so. They took a sample of 14 tires to test if the mean mileage of the tires is really less than 50, 000. If 0.0100 < P-value < 0.0200, what decision should be made if testing at the a = 0.05 level?
7. An Air Force vase mess hall has received a shipment of 10, 000 gallon size cams of cherries. The supplier claims that the average amount of liquid is 0.25 gallons per can. A government inspector took a random sample of 100 cans and found that the average liquid content to be 0.28 gallons per can with a standard deviation of 0.10. Does this indicate that the supplier's claim is too low? (Use a 5% level of significance)
8. How do you reduce both types of errors from occurring?
9. Slab avalanches studied in Canada have an average thickness of $\mu$ = 67 cm. The ski patrol at Vail Colorado, is studying slab avalanches in their region. A random sample of 16 avalanches showed that x-bar = 61.8cm and s = 10.6 cm. Assuming the slab thickness is normally distributed, test the claim that the mean slab thickness is the Vail region is different from that in Canada with a level of significance of 1%.
10. Which of the following best describes a Type I error?
11. A leading auto manufacturer claimed that a popular version of its minivan was available in the Midwest foran average price or $ 16, 000 with a standard deviation of $ 800. A consumer group doubted that report and surveyed 50 recent purchasers of the minivan to dispute the manufacturer's claim. They came up with an average of $ 16, 277. Does this show that the manufacturer is making a false claim?
12. Your conclusion about a hypothesis test should have all of the following characteristics EXCEPT
13. In 1975, a random sample of 1484 adult U.S. citizens was surveyed, and 193 strongly agreed with the statement, "People should take care of themselves." Then, in 1991, a survey of 1013 adult U.S. citizens showed that only 61 strongly agreed with the statement. Does this indicate that the proportion of U.S. adults who strongly agree with the given statement has dropped?
14. A sports publication states that 32% of married men cannot watch football games because their wives prevent it. You think that this is untrue. What is your null hypothesis?
15. A random sample of 49 medical doctors in LA showed that they worked an average of 53.1 hours/week with a standard deviation of 7.2 hours/week. If the California average is 60 hours/week, does this give evidence that the LA doctors work significantly less than the rest of California?
16. The average miles on a tank of gas for the FordExplorer is 300 miles with a standard deviation of 22miles. A consumer group feels the average is actuallylower. They survey 40 vehicles and find the averagemiles per tank is 290 miles. At $\alpha$ = 0.05, test theconsumer groups' claim that the miles per tank isactually lower than 300 miles.
17. What is the probability of mistakenly failing to reject a false Ho when a hypothesis test is being conducted at the 5% significance level (at 0.05)?
18. This hypothesis describes what we want to establish or what we expect is true.