Exam 9: Hypothesis Testing Ii the Two Sample Case

Four tests 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?

When conducting hypothesis tests for two sample means, the term μ 1- μ 2in the numerator of the formula reduces to zero because________.

From a University population, random samples of 45 seniors and 37 freshmen have been given a scale that measures sexual experiences. The freshmen report an average of 1.6 sexual partners over their lifetimes while seniors report an average of 2.5 partners. The t (obtained) for this difference was -3.56 while the t (critical) was±2.34. What can be concluded?

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________.

Since critical values of t vary by sample size, before using the t table we must first calculate________.

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?

A one-tailed test ____________ the probability of rejecting the null hypothesis.

For testing the difference between two sample means, the level of measurement is assumed to be________.

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 =±1.96) to test for significance and found that his computed test statistic was 2.76. He may conclude that________.

Random samples of 1546 men and 1678 women have been given a scale that measures support of legal abortion. Men average 12.45 and women average 12.46, and the difference is significant at the 0.05 level. What can 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?

For tests of significance involving two sample proportions, the value of the population proportion is estimated from________.

From a University population, random samples of 145 men and 237 women have been asked if they have ever cheated in a college class. 8% of the men and 6% of the women said that they have. What is the appropriate test to assess the significance of this difference?

A scale measuring confidence in the media was administered to a sample. Is there a statistically significant difference between Democrats and Republicans on the scale? Higher scores on the scale indicate greater confidence. Use the five step model and write a sentence or two interpreting your results.

A sample of students attending a large university has been selected. Is there a statistically significant difference between Liberal Arts majors and other students on average number of books (other than those required by course work) read per year? Use the five step model and write a sentence or two interpreting your results.

Samples from two high schools are being tested for the difference in their average levels of prejudice. One sample contains 39 respondents and the other sample contains 47 respondents. The appropriate sampling distribution is the________.

In the two sample case, the null hypothesis is always about the difference in the________.