Can someone help me to make sure I have the right answers for

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Can someone help me to make sure I have the right answers for my quiz in RES/342 from University of Phoenix? The due date is Sunday Jan 10th.

I have bolded the answers I have solved.

RES 342 - Quiz 2 Name_______________

Multiple Choice - 2 points each

1. If the alternate hypothesis states that m does not equal 4,000, what is the rejection region for the hypothesis test?

A. Both tails

B. Lower or left tail

C. Upper or right tail

D. Center

E. None of the above

2. What are the two rejection areas in using a two-tailed test and the 0.01 level of significance?

A. Above 1.96 and below -1.96

B. Above 1.65 and below -1.65

C. Above 2.58 and below -2.58

D. Above 1.00 and below -1.00

E. None of the above

3. If the 1% level of significance is used and the computed value of z is +6.00, what is our decision?

A. Do not reject H_{0}

B. Reject H_{0}

C. Reject H_{1}

D. None of the above

4. A poll of 400 people from Dobbs Ferry showed 250 favored chocolate raspberry coffee while 170 out of 350 in Irvington favored the same flavor. To test the hypothesis that there is no difference in preferences in the two villages, what is the alternate hypothesis?

A. p_{1} < p_{2}

B. p_{1} > p_{2}

C. p_{1} = p_{2}

D. p_{1} not equal to p_{2}

E. None of the above

5. If the decision is to reject the null hypothesis at the 5% level of significance, what are the acceptable alternate hypothesis and rejection region?

A. p_{1} ¹ p_{2} ; z > 1.65 and z < -1.65

B. p_{1} ¹ p_{2}; z > 1.96 and z < -1.96

C. p_{1} > p_{2}; z < -1.65

D. p_{1} > p_{2}; z < -1.96

E. None of the above

6. The following does NOT hold true for the t distribution?

A. Confidence interval will be wider than for large samples.

B. Region of acceptance will be wider than for large samples.

C. Larger computed t value will be needed to reject the null hypothesis than for large samples using z.

D. There is only one t distribution.

E. None of the above.

7. Suppose a one-tailed t-test is being applied to find out if the population mean is less than $212. The level of significance selected is 0.01 and 26 accounts are sampled. What is the critical value?

A. -2.580

B. -2.485

C. -1.960

D. -2.479

E. None of the above

8. The mean length of a small counter balance bar is 43 millimeters. There is concern that the adjustments of the machine producing the bars have changed. Test the claim at the 0.02 level that there has been no change in the mean length. The alternate hypothesis is that there has been a change. Twelve bars (n = 12) were selected at random and their lengths recorded. The lengths are (in millimeters) 42, 39, 42, 45, 43, 40, 39, 41, 40, 42, 43 and 42. The mean of the sample is 41.5 and the standard deviation 1.784. Computed t = - 2.913. Has there been a statistically significant change in the mean length of the bars?

A. Yes, because the computed t lies in the area beyond the critical.

B. No, because the information given is not complete.

C. No, because the computed t lies in the area to the right of -2.913.

D. None of the above

9. From past records it is known that the average life of a battery used in a digital clock is 305 days. The lives of the batteries are normally distributed. The battery was recently modified to last longer. A sample of 20 of the modified batteries was tested. It was discovered that the mean life was 311 days and the sample standard deviation was 12 days. We want to test at the 0.05 level of significance whether the modification increases the life of the battery. What is our decision rule?

A. Do not reject the null hypothesis if computed t is 1.96 or greater

B. Reject the null hypothesis if computed t is less than 1.96

C. Do not reject the null hypothesis if computed t is 1.729 or greater

D. Reject the null hypothesis if computed t is 2.494 or greater

E. None of the above

10. The net weights of a sample of bottles filled by a machine manufactured by Edne, and the net weights of a sample filled by a similar machine manufactured by Orno, Inc., are (in grams):

10. Edne: 5, 8, 7, 6, 9 and 7

10. Orno: 8, 10, 7, 11, 9, 12, 14 and 9

10.Testing the claim at the 0.05 level the mean weight of the bottles filled by the Orno machine is greater than the mean weight of the bottles filled by the Edne machine, what is the critical value?