Exam 11: Two-Sample Tests of Hypothesis

The results of a mathematics placement exam at two different campuses of Mercy College follow: Given that the two population standard deviations are known,what is the p-value?

When testing the hypothesized equality of two population means,the implied null hypothesis is ________.

A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are presented here. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but assumed equal. What is the critical t-value at the 1% level of significance?

When testing the difference between two dependent population means,the test statistic is based on a ________.

A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled,and the average error from the industry standard is measured in millimeters. The results are presented here. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. If we test the null hypothesis at the 1% level of significance,what is the decision?

A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected,and their times (in seconds)to access the website with the old and new designs were recorded. To compare the times,they computed new website design time − old website design time. The results follow. For a 0.01 significance level,what is the critical value?

A recent study focused on the amount of money single men and women save monthly. The information is summarized here. Assume that the population standard deviations are equal. At the 0.01 significance level,do women save more money than men? What is the critical value for this hypothesis test?

For a hypothesis comparing two population means,H₀: μ₁ ≤ μ₂,what is the critical value for a one-tailed hypothesis test,using a 5% significance level,with both sample sizes equal to 13? Assume the population standard deviations are equal.

If we are testing for the difference between two population means,it is assumed that the sample observations from one population are independent of the sample observations from the other population.

A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled,and the average error from the industry standard is measured in millimeters. The results are presented here. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. What are the degrees of freedom?

A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected,and their times (in seconds)to access the website with the old and new designs were recorded. To compare the times,they computed new website design time − old website design time. The results are shown here. What is the null hypothesis?

When dependent samples are used to test for differences in the means,we pool the sample variances.

A recent study focused on the amount of money single men and women save monthly. The information is summarized here. Assume that the population standard deviations are equal. At the 0.01 significance level,what is the conclusion about the way women and men save?

A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are presented here. The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. What is the computed value of t?

When dependent samples are used to test for differences in the means,we compute paired differences.

The results of a mathematics placement exam at two different campuses of Mercy College follow: What is the alternative hypothesis if we want to test the hypothesis that the mean score on Campus 1 is higher than on Campus 2?

If two dependent samples of size 20 are used to test the difference between the means,the degrees of freedom for a t-statistic are 19.

When testing the difference between two population means,the sample variances are pooled to estimate the population variance when ________.

Accounting procedures allow a business to evaluate their inventory costs based on two methods: LIFO (last in first out)or FIFO (first in first out). A manufacturer evaluated its finished goods inventory (in $000s)for five products with the LIFO and FIFO methods. To analyze the difference,they computed FIFO − LIFO for each product. We would like to determine if the LIFO method results in a lower cost of inventory than the FIFO method. What is the alternate hypothesis?

If the null hypothesis states that there is no difference between the mean income of males and the mean income of females,then the test is one-tailed.