Question

A group in favor of freezing production of nuclear weapons believes that the proportion of individuals in favor of a nuclear freeze is greater for those who have seen the movie "The Day After" (population 1) than those who have not (population 2). In an attempt to verify this belief, random samples of size 500 are obtained from the populations of interest. Among those who had seen "The Day After", 228 were in favor of a freeze. For those who had not seen the movie, 196 favored a freeze. What is the correct null and alternate hypothesis? A. H0:p = 0.5 Ha:p not equal 0.5 B. H0:p = 0.5 Ha:p > 0.5 C. H0:p1 = p2 Ha:p1 not equal p2 D. H0:p1 = p2 Ha:p1 > p2 4 points QUESTION 17 A group in favor of freezing production of nuclear weapons believes that the proportion of individuals in favor of a nuclear freeze is greater for those who have seen the movie "The Day After" (population 1) than those who have not (population 2). In an attempt to verify this belief, random samples of size 500 are obtained from the populations of interest. Among those who had seen "The Day After", 228 were in favor of a freeze. For those who had not seen the movie, 196 favored a freeze. The null hypothesis uses is: H0: p1-p2=0 vs. Ha: p1-p2 > 0 Please compute the test statistic for this null and alternate hypothesis. 4 points QUESTION 18 A university investigation was conducted to determine whether women and men complete medical school in significantly different amounts of time, on the average. Two independent random samples were selected and the following summary information concerning times to completion of medical school computed: Women Men Sample Size 90 100 Sample Mean 8.4 years 8.5 years Sample Standard Deviation 0.6 years 0.5 yearsTest using α = 0.05. The null and alternate hypothesis used: H0: mu1-mu2=0 vs. Ha: mu1-mu2 not equal 0 The test statistic is: -1.24 What is the correct conclusion? A. Fail to reject the null hypothesis B. Accept the null hypothesis C. Reject the null hypothesis D. There is not enough information given 4 points QUESTION 19 The Environmental Protection Agency wanted to compare the proportion of plants in violation of air quality standards for two different industries: steel and utility. Two independent samples of plants were selected and monitored. The following data was recorded: Steel: n1= 150 Number of violations =x1 = 12 Utility: n2= 160 Number of violations = x2 = 12 Which test should be used? A. T test for the difference between two proportions B. Z test for proportions C. Z test for the difference between two proportions D. T test for proportions 4 points QUESTION 20 While testing the null and alternate hypothesis: H0: p=0.5 vs. Ha:p<0.5 p-value = 0.2457 alpha = 0.05 What is the correct decision? A. Do not reject H0 B. Reject Ha C. none of these D. Reject H0 4 points QUESTION 21 The chi-squared distribution is: A. symmetric around zero. B. negatively skewed C. mound-shaped D. positively skewed 4 points QUESTION 22 In a hypothesis test for the population variance, the hypotheses to be tested are H0: sigma^2 =25 vs. Ha: sigma^2 < 25(note: sigma is the circle thing with a tail on the top, also known as the population standard deviation) If the sample size is 20 and the test is being carried out at the 10% level of significance, the null hypothesis will be rejected if: A. Chi Squared > 12.4426 B. Chi Squared > 11.6509 C. Chi Squared > 10.851 D. Chi Squared > 10.117 4 points QUESTION 23 A customer service representative was interested in comparing the average time (in minutes) customers are placed on hold when calling Southern California Edison and Southern California Gas companies. The representative obtained two independent random samples and calculated the following summary information: So Cal Edison Southern Cal Edison Southern Cal Gas Sample Size 9 12 Sample Mean 3.2 min 2.8 min Sample Standard deviation 0.5 min 0.7 min Assume the distributions of time a customer is on hold are approximately normal.Using the null and alternate hypothesis: H0:mu1-mu2=0 vs. Ha:mu1-mu2 not equal 0Calculate the value of the test statistic. 4 points QUESTION 24 A computer laboratory manager was in charge of purchasing new battery packs for her lab of laptop computers. She narrowed her choices to two models that were available for her machines. Since the models cost about the same, she was interested in determining whether there was a difference in the average time the battery packs would function before needing to be recharged. She took two independent samples and computed the following summary information: Battery Pack Model 1 Battery Pack Model 2 Sample Size 9 9 Sample Mean 5 hours 5.5 hours Standard Deviation 1.5 hours 1.3 hours Using the null and alternate hypothesis: H0: mu1-mu2=0 vs. Ha:mu1-mu2 not equal 0The test statistic is: -0.7557Using alpha =0.05 choose the appropriate decision? A. None of these B. Reject H0 C. Do not reject H0 D. Reject Ha 4 points QUESTION 25 A drapery store manager was interested in determining whether a new employee can install vertical blinds faster than an employee who has been with the company for two years. The manager takes independent samples of 10 vertical blind installations of each of the two employees and computes the following information. New Employee Veteran Employee Sample Size 10 10 Sample Mean 22.2 min 24.8 min Standard Deviation 0.90 min 0.75 minUsing the following null and alternate hypothesis: H0:mu1-mu2=0 vs. Ha:mu1-mu2<0 Test statistic is t=-7.018 Assume alpha = 0.05 what is the appropriate conclusion for this test? A. Reject H0 B. Do not reject H0 C. Reject Ha D. none of these 4 points QUESTION 26 True or False. I got problem one correct on self assess quiz 2. True False 1 points (Extra Credit) QUESTION 27 True or False. I got problem two correct on self assess quiz 2. True False 1 points (Extra Credit) QUESTION 28 True or False. I got problem three correct on self assess quiz 2. True False 1 points (Extra Credit) QUESTION 29 True or False. I got problem 4 correct on self assess quiz 2. True False 1 points (Extra Credit) QUESTION 30 True or False. I got problem 5 correct on self assess quiz 2. True False 1 points (Extra Credit) Click Save and Submit to save and submit. 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Answer 1

1)Null hypothesis :

Let p1 be the Proportion of nuclear freeze who has seen the movie and p2 be the proportion of nuclear freeze who hasn't seen the movie

So H₀:- p1-p2

or p1=p2

Alternative hypothesis :

H1:-p1>p2

i.e Proportion of nuclear freeze who has seen the movie is greater than  p2 the proportion of nuclear freeze who hasn't seen the movie.

So option d is correct.

2)The statistical software output for this problem is:

Hypothesis test results:

Difference	Count1	Total1	Count2	Total2	Sample Diff.	Std. Err.	Z-Stat	P-value
p1 - p2	228	500	196	500	0.064	0.031255336	2.0476504	0.0203

Hence,

Test statistic = 2.0477

3) At 5% significant level critical value of

Given test statistic t=-1.24

Rejection region is t < -1.96 or t > +1.96

Since the test statistic does not lie in the rejection region we fail to reject the Null hypothesis

Option (a) is correct.

Please post the remaining questions seperately.