Exam 10: Two-Sample Tests

SCENARIO 10-2 A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries.Of primary interest to the researcher was the effect of gender on starting salaries.The result of the pooled-variance t-test of the mean salaries of the females (Population 1)and males (Population 2)in the sample is given below. -

SCENARIO 10-2 A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries.Of primary interest to the researcher was the effect of gender on starting salaries.The result of the pooled-variance t-test of the mean salaries of the females (Population 1)and males (Population 2)in the sample is given below. -Referring to Scenario 10-2, the researcher was attempting to show statistically that the female MBA graduates have a significantly lower mean starting salary than the male MBA graduates.From the analysis in Scenario 10-2, the correct test statistic is:

SCENARIO 10-1 Are Japanese managers more motivated than American managers? A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility.The SSATL scores are summarized below. -Referring to Scenario 10-1, find the p-value if we assume that the alternative hypothesis was a Two-tail test.

SCENARIO 10-6 To investigate the efficacy of a diet, a random sample of 16 male patients is selected from a population of adult males using the diet.The weight of each individual in the sample is taken at the start of the diet and at a medical follow-up 4 weeks later.Assuming that the population of differences in weight before versus after the diet follow a normal distribution, the t-test for related samples can be used to determine if there was a significant decrease in the mean weight during this period.Suppose the mean decrease in weights over all 16 subjects in the study is 3.0 pounds with the standard deviation of differences computed as 6.0 pounds. -

SCENARIO 10-8 A few years ago, Pepsi invited consumers to take the "Pepsi Challenge." Consumers were asked to decide which of two sodas, Coke or Pepsi, they preferred in a blind taste test.Pepsi was interested in determining what factors played a role in people's taste preferences.One of the factors studied was the gender of the consumer.Below are the results of analyses comparing the taste preferences of men and women with the proportions depicting preference for Pepsi. -Referring to Scenario 10-8, construct a 95% confidence interval estimate of the difference between the proportion of males and females who prefer Pepsi.

SCENARIO 10-7 -Referring to Scenario 10-7, the decision rule is to reject the null hypothesis if ________.

SCENARIO 10-3 -Referring to Scenario 10-3, what is the estimated standard error of the difference between the 2 Sample means?

SCENARIO 10-9 The following EXCEL output contains the results of a test to determine whether the proportions of satisfied customers at two resorts are the same or different. 10-32 Two-Sample Tests -Referring to Scenario 10-9, if you want to test the claim that "Resort 1 (Group 1)has a higher Proportion of satisfied customers compared to Resort 2 (Group 2)", the p-value of the test will be

A powerful women's group has claimed that men and women differ in attitudes about sexual Discrimination.A group of 50 men (group 1)and 40 women (group 2)were asked if they thought Sexual discrimination is a problem in the United States.Of those sampled, 11 of the men and 19 Of the women did believe that sexual discrimination is a problem.Find the value of the test Statistic.

SCENARIO 10-8 A few years ago, Pepsi invited consumers to take the "Pepsi Challenge." Consumers were asked to decide which of two sodas, Coke or Pepsi, they preferred in a blind taste test.Pepsi was interested in determining what factors played a role in people's taste preferences.One of the factors studied was the gender of the consumer.Below are the results of analyses comparing the taste preferences of men and women with the proportions depicting preference for Pepsi. -Referring to Scenario 10-8, suppose Pepsi wanted to test to determine if the males preferred Pepsi less than the females.Using the test statistic given, compute the appropriate p-value for the Test.

SCENARIO 10-6 To investigate the efficacy of a diet, a random sample of 16 male patients is selected from a population of adult males using the diet.The weight of each individual in the sample is taken at the start of the diet and at a medical follow-up 4 weeks later.Assuming that the population of differences in weight before versus after the diet follow a normal distribution, the t-test for related samples can be used to determine if there was a significant decrease in the mean weight during this period.Suppose the mean decrease in weights over all 16 subjects in the study is 3.0 pounds with the standard deviation of differences computed as 6.0 pounds. -Referring to Scenario 10-6, what is the 95% confidence interval estimate for the mean difference in weight before and after the diet?

SCENARIO 10-3 -Referring to Scenario 10-3, what is the 99% confidence interval estimate for the difference in the two means?

Moving companies are required by the government to publish a Carrier Performance Report each Year.One of the descriptive statistics they must include is the annual percentage of shipments on Which a $50 or greater claim for loss or damage was filed.Suppose two companies, Econo-Move And On-the-Move, each decide to estimate this figure by sampling their records, and they report The data shown in the following table. The owner of On-the-Move is hoping to use these data to show that the company is superior to Econo-Move with regard to the percentage of claims filed.Which test would be used to properly Analyze the data in this experiment?

SCENARIO 10-3 -Referring to Scenario 10-3, what is the test statistic for the difference between sample means?

SCENARIO 10-2 A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries.Of primary interest to the researcher was the effect of gender on starting salaries.The result of the pooled-variance t-test of the mean salaries of the females (Population 1)and males (Population 2)in the sample is given below. -Referring to Scenario 10-2, the researcher was attempting to show statistically that the female MBA graduates have a significantly lower mean starting salary than the male MBA graduates. Which of the following is an appropriate alternative hypothesis?

In testing for the differences between the means of two related populations, you assume that the differences follow a _______ distribution.

SCENARIO 10-1 Are Japanese managers more motivated than American managers? A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility.The SSATL scores are summarized below. -Referring to Scenario 10-1, judging from the way the data were collected, which test would likely Be most appropriate to employ?

SCENARIO 10-4 Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0. -Referring to Scenario 10-4, what is the 99% confidence interval estimate for the difference in the two means?