The owner of a local nightclub has recently surveyed a random sample o

1.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If she wants to have a level of significance at 0.01, what rejection region should she use? 选项： A、Reject H0 if t < -2.3263. B、Reject H0 if t < -2.5758. C、Reject H0 if t > 2.3263. D、Reject H0 if t > 2.5758.

2.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If she wants to have a level of significance at 0.01, what rejection region should she use? 选项： A、Reject H0 if t < -2.3263. B、 Reject H0 if t < -2.5758. C、 Reject H0 if t > 2.3263. D、Reject H0 if t > 2.5758.

3.37.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If she wants to have a level of significance at 0.01, what rejection region should she use? 选项： A、Reject H0 if t < -2.3263. B、Reject H0 if t < -2.5758. C、Reject H0 if t > 2.3263. D、Reject H0 if t > 2.5758.

4.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If she wants to be 99% confident in her decision, what rejection region should she use?选项： A:Reject H0 if t > 2.34.; B:Reject H0 if t < – 2.34.; C:Reject H0 if t < – 2.55.; D:Reject H0 if t > 2.58.

5.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If she wants to be 99% confident in her decision, what rejection region should she use? 选项： A、Reject H0 if t > 2.34. B、Reject H0 if t < – 2.34. C、Reject H0 if t < – 2.55. D、Reject H0 if t > 2.58.

6.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to have a level of significance at 0.01, what decision should she make?选项： A:Reject H0.; B: Reject H1.; C: Do not reject H0.; D:We cannot tell what her decision should be from the information given.

7.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to have a level of significance at 0.01 what conclusion can she make 选项： A、There is not sufficient evidence that the mean age of her customers is greater than 30. B、There is sufficient evidence that the mean age of her customers is greater than 30. C、There is not sufficient evidence that the mean age of her customers is not greater than 30. D、There is sufficient evidence that the mean age of her customers is not greater than 30.

8.42.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. The appropriate hypotheses to test are: 选项： A、H0: μ ≥ 30 versus H1: μ < 30. B、H0: μ ≤ 30 versus H1: μ > 30. C、H0: ≥ 30 versus H1: < 30. D、H0: ≤ 30 versus H1: > 30.

9.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. The appropriate hypotheses to test are: 选项： A、H0: μ ≥ 30 versus H1: μ < 30. B、H0: μ ≤ 30 versus H1: μ > 30. C、H0: ≥ 30 versus H1: < 30. D、H0: ≤ 30 versus H1: > 30.

10.The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. The appropriate hypotheses to test are: 选项： A、H0: μ ≥ 30 versus H1: μ < 30. B、H0: μ ≤ 30 versus H1: μ > 30. C、H0: ≥ 30 versus H1: < 30. D、H0: ≤ 30 versus H1: > 30.

11.The manufacturers of a deodorant claim that the mean drying time of their product is, at most, 15 minutes. A sample consisting of 16 cans of the product was used to test the manufacturer’s claim. The experiment yielded a mean drying time of 18 minutes with a standard deviation of 6 minutes. Test the claim at the 0.05 significance level.选项： A:Computed test statistic = 2 and is greater than 1.645, so reject H0: µ ≤ 15. B:Computed test statistic = 2 and is greater than 1.96, so reject H0: µ ≤ 15. C:Computed test statistic = 2 and is greater than 1.753, so reject H0: µ = 15. D:Computed test statistic = 2 and is greater than 2.131, so reject H0: µ ≤ 15.

12.The manufacturers of a deodorant claim that the mean drying time of their product is, at most, 15 minutes. A sample consisting of 16 cans of the product was used to test the manufacturer’s claim. The experiment yielded a mean drying time of 18 minutes with a standard deviation of 6 minutes. Test the claim at the 0.05 significance level.选项： A:Computed test statistic = 2 and is greater than 1.753, so reject H0: µ = 15. B:Computed test statistic = 2 and is greater than 1.645, so reject H0: µ ≤ 15. C:Computed test statistic = 2 and is greater than 2.131, so reject H0: µ ≤ 15. D:Computed test statistic = 2 and is greater than 1.96, so reject H0: µ ≤ 15.

13.How many Kleenex should the Kimberly Clark Corporation package of tissues contain? Researchers determined that 60 tissues is the average number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold:

= 52, s = 22. Suppose the alternative we wanted to test was H1:

. State the correct rejection region for

选项： A、Reject H0 if t > 1.6604. B、Reject H0 if t < – 1.6604. C、Reject H0 if t > 1.9842 or Z < – 1.9842. D、Reject H0 if t < – 1.9842.

14.The mean annual incomes of certified welders are normally distributed with the mean of $50,000 and a population standard deviation of $2,000. The ship building association wishes to find out whether their welders earn more or less than $50,000 annually. A sample of 100 welders is taken and the mean annual income of the sample is $50,350. If the level of significance is 0.10, what conclusion should be drawn? 选项： A:

Do not reject the null hypothesis as the test statistic is less than the critical value of t.

B:

Reject the null hypothesis as the test statistic is greater than the critical value of z.

C:

Do not reject the null hypothesis as the test statistic is less than the critical value of z.

D:

Reject the null hypothesis as the test statistic is greater than the critical value of t.

15.You have created a 95% confidence interval for μ with the result 10 ≤ μ ≤ 15. What decision will you make if we test H0: μ =16 versus H1: μ ≠ 16 at α = 0.10? 选项： A: Reject H0 in favor of H1.; B:Do not reject H0 in favor of H1.; C:Fail to reject H0 in favor of H1.; D:We cannot tell what our decision will be from the information given.

16.Mrs. Johnson is reluctant to let Dee have the quilts because ( ).选项： A:she doesn’t like Dee B:she knows the quilts have great monetary value C:she wants to keep them for her own use D:she has promised them to Maggie

17.What does the woman mean（）选项： A、She can’t go to the play. B、She doesn’t like the play. C、She has watched the play.

18.A researcher is performing a two-tailed related samples (matched pairs) t-test. A total of 12 people are in the sample, and before and after measures are taken. The observed t-value for this is –1.84. The level of significance is 0.05. The correct decision is to _______.选项： A:do not reject the null hypothesis B:reject the null hypothesis C:take a larger sample D:use the z-table instead of the t-table

19.What is the man probably going to do after graduation 选项： A、She has more letters now than before. B、She hasn’t so many letters as before. C、She often hears from her family now. D、She is used to having a lot of letters.

20. If a test of hypothesis has a Type I error probability (α) of 0.01, it means that选项： A: if the null hypothesis is true, you don't reject it 1% of the time.; B: if the null hypothesis is true, you reject it 1% of the time.; C:if the null hypothesis is false, you don't reject it 1% of the time.; D:if the null hypothesis is false, you reject it 1% of the time.

21.Why Adrienne doesn’t have the violin with her now? 选项： A、Because she stopped playing it. B、Because she’s in Japan now. C、Because she lost it. D、Because she doesn’t like to carry it around overseas.

22.She has her own business,()? 选项： A、doesn 't she B、does she C、hasn 't she D、has she