When Testing The Equality Of Population Variances The Test
When Testing The Equality Of Population Variances The Test Statisti
When testing the equality of population variances, the test statistic is the ratio of the sample variances (or equivalently, the ratio of the squared standard deviations). A) True B) False
When we test for differences between the means of independent populations, we can only use a one-tail test. A) True B) False
The sample size in each independent sample must be the same if we are to test for differences between means. A) True B) False
A statistics professor wanted to test whether the grades on a statistics quiz were the same for the online and resident MBA students. The professor took a random sample of 15 students from each course and is going to conduct a test to determine if the VARIANCES in the grades for online and resident MBA students are equal. For this test, the professor should use a t-test with related or matched samples. A) True B) False
Situation 6.1.1: Do Japanese managers have different motivation levels 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. Higher scores indicate more motivation. The SSATL scores are summarized below. Japanese Mgrs American Mgrs Sample Size Mean SSATL Score 65..83 Population Std. Deviation 11... What is the appropriate null and alternative hypothesis for testing the question posed in Situation 6.1.1? A) µJ - µA ≥ 0; H1:µJ - µA 0 C) µJ - µA = 0; H1: µJ - µA ≠ 0 D) μJ - μA = 0; H1: μJ - μA ≠
Given the following results generated in Excel, are the variances in the sample of Japanese managers different than the variances in the sample of U.S. managers at the .05 level of significance? Data Level of Significance 0.05 Population 1 Sample Sample Size 211 Sample Standard Deviation 11.07 Population 2 Sample Sample Size 100 Sample Standard Deviation 6.41 Intermediate Calculations F -Test Statistic 2.982491 Population 1 Sample Degrees of Freedom 210 Population 2 Sample Degrees of Freedom 99 Two-Tailed Test Lower Critical Value 0.719629 Upper Critical Value 1.419014 p -Value 6.01E-09 A) Yes, there are significant differences in the sample variances. B) No, there are no significant differences in the sample variances.
Referring to the data, the results of the previous question, and how the data were collected in Situation 6.1.1, which of the following test would be most appropriate to employ? A) Separate (unequal) variance t test for means. B) Pooled (equal) variance t test for means C) Paired or matched sample t test for means D) F test for variances
If we had been given the following results from Excel (ignoring any previous findings), are motivation levels for Japanese managers different from those of U.S. managers at the .05 level of significance?. Data Hypothesized Difference 0 Level of Significance 0.05 Population 1 Sample Sample Size 211 Sample Mean 65.75 Sample Standard Deviation 11.07 Population 2 Sample Sample Size 100 Sample Mean 79.83 Sample Standard Deviation 6.41 Intermediate Calculations Population 1 Sample Degrees of Freedom 210 Population 2 Sample Degrees of Freedom 99 Total Degrees of Freedom 309 Pooled Variance 96.44709 Difference in Sample Means -14.08 t -Test Statistic -11.8092 Two-Tailed Test Lower Critical Value -1.96767 Upper Critical Value 1.967669 p -Value 8.22E-27 A) Yes, there is a significant difference in mean SSATL scores. B) No, there is no significant difference between mean SSATL scores.
Situation 6.1.2: A survey was recently conducted to determine if consumers spend more on computer-related purchases via the Internet or store visits. Assume a sample of 8 respondents provided the following data on their computer-related purchases during a 30-day period. Using a .05 level of significance, can we conclude that consumers spend more on computer-related purchases by way of the Internet than by visiting stores? Expenditures (dollars) Respondent In-Store Internet. Refer to Situation 6.1.2. The test statistic for determining whether or not consumers spend more on computer-related purchases by way of the Internet than by visiting stores is A) 0.80 B) 1.12 C) 1.76 D) 1. If we are interested in testing whether the mean of population 1 is significantly smaller than the mean of population 2, the A) null hypothesis should state μ1 - μ2 0 E) both b and d are correct