8.1 The Idea of Significance Tests

The Survey of Study Habits and Attitudes (SSHA) is pyschological test that measures students' attitudes toward school and study habits. Scores range from 0 to 200. there mean score for U.S. college students is about 115. A teacher suspects that older students have better attitudes toward school. She gives the SSHA to an SRS of 45 of the more than 1000 students at her college who are at least 30 years of age and the average score is 140.

Choose the correct null and alternative hypotheses given that \mu =the true mean SSHA score for college students.

A Gallup Poll report revealed that 72% of teens said they seldom or never argue with their friends. Yvonne wonders whether this result holds true at her high school. She surveys a random sample of 150 students at her high school and 114 report that they seldom or never argue with their friends.

Choose the correct null and alternative hypotheses, given that p=the true proportion of teens that seldom or never argue with their friends.

The mean weight of loaves of bread produced at the bakery where you work is supposed to 1 pound. You are the supervisor of quality control at the bakery, and you are concerned that the employees are making loaves that are too light. Suppose you weigh an SRS of 50 bread loaves and find the mean weight is 0.975.

Choose the correct null and alternative hypotheses, given that \mu = the true mean weight of the loaves in this bakery.

The Survey of Study Habits and Attitudes (SSHA) is pyschological test that measures students' attitudes toward scool and study habits. Scores range from 0 to 200. there mean score for U.S. college students is about 115. A teacher suspects that older students have better attitudes toward school. She gives the SSHA to an SRS of 45 students at her college who are at least 30 years of age and the average SSHA score was 140. The resulting p-value is 0.00101. Use a significance level of \alpha value is 0.05. (Your alpha is like your 5% rule)

What conclusion would you make based on the hypotheses for this test written on #1?

The mean weight of loaves of bread produced at the bakery where you work is supposed to 1 pound. You are the supervisor of quality control at the bakery, and you are concerned that the employees are making loaves that are too light. Suppose you weigh an SRS of 50 bread loaves and find the mean weight is 0.975. The resulting p-value for your test is 0.08.

What conclusion would you make based on the hypotheses for this test written on #3 at \alpha=0.05? (Your Alpha is like you 5% rule)