Exam 8: Hypothesis Testing II the Two-Sample Case

When testing hypotheses using two small samples, the t distribution may be used only after the additional assumption that

When testing for the significance of the difference between two samples, which is the proper assumption for step 1?

When solving the formula for finding Z(obtained) with sample proportions in the two-sample case, we must first estimate

When testing for the significance of the difference between two sample means, which parameters must be estimated with sample values?

A researcher conducted a survey to determine if older people have different feelings about abortion than younger people. He used an alpha level of 0.05 (Z critical = $\pm$ 1.96) to test for significance and found that his computed test statistic was 2.76. He may conclude that

Samples of Republicans and Democrats have been tested for their level of support for a new immigration policy. The test statistic is 0.54 and the critical region begins at ± 1.96. What may we conclude?

Very large random samples of Catholics and Protestants have been questioned about their opinions on cohabitation. Forty-six percent of the Protestant and 47% of the Catholics approve of males and females living together without being married. The difference has been tested and found to be statistically significant. What is the most reasonable conclusion?

If a difference between random samples is not statistically significant, it is probably __________. On the other hand, a statistically significant difference is not necessarily ___________.

According to information reported in the text, about 17% of men earn more than $100,000 a year vs. about ___% of women

According to the text, tests of mathematical abilities of American boys and girls showed

When testing the significance of the difference between two sample proportions, the null hypothesis is

In testing for the significance of the difference between two sample means when the sample size is small, we may assume equal population variances if

When is the t distribution used instead of the Z distribution to test the significance of the difference between two sample means?

When testing for the significance of the difference between two sample means, which of the following is almost always unknown?

When random samples are drawn so that the selection of a case for one sample has no effect on the selection of cases for another sample, the samples are

The larger the sample size, the

Four test of significance were conducted on the same set of results: For test 1: alpha = 0.05, two-tailed test. For test 2: alpha = 0.10, one-tailed test. For test 3: alpha = 0.01, two-tailed test. For test 4: alpha = 0.01, one-tailed test. Which test is most likely to result in a rejection of the null hypothesis?

To satisfy the requirement of independent random sampling, the researcher

When conducting hypothesis tests for two sample means, the test statistic is

To maximize the probability of rejecting the null hypothesis, use