AP Statistics Chapter 11

A random sample of college professors is taken. We wish to compare the average salaries of male and female teachers.

What kind of test should be used?

• Paired t-test

• Difference of means test

To compare the average weight gain of pigs fed two different rations, nine pairs of pigs were used. The pigs in each pair were littermates. A coin toss was used to decide which pig in each pair got Ration A and which got Ration B.

What kind of test should be used?

• Paired t-test

• Difference of means test

To test the wear characteristics of two tire brands, A and B, each brand of tire is randomly assigned to 50 cars of the same make and model. (Two tires of each brand are randomly assigned to either the left or the right side of each car) What kind of test should be used?

• Paired t-test

• Difference of means test

A 95% confidence interval for m based on n = 15 observations from a Normal population is (-0.73, 1.92) If we use this confidence interval to test the hypotheses H_0: \mu=0 against H_a: \mu\ne0, which of the following is the most appropriate conclusion?

• Reject H_o at the a = 0.05 level of significance

• Fail to reject H_o at the a = 0.05 level of significance

• Reject H_o at the a = 0.10 level of significance

• Fail to reject H_o at the a = 0.10 level of significance

• We cannot perform the required test since we do not know that value of the standardized test statistic

What is the formula for one-sample t test for a mean difference (paired t test)?

Which of the following is not a condition for constructing mean difference of paired data?

• Random: paired data come from a random sample from the population of interest or from a randomized experiement

___ result from recording two values of the same quantitative variable for each individual or for each pair of similar individuals.

• Separated 

• Combined (pooled)

What kind of test should be used?

• Paired t-test

• Difference of means test

To test a claim about a mean, when the population standard deviation is unknown we use:

• z procedures

• Pythagorean Theorem

• t procedures

• np > 10 and n(1-p) > 10