Author Question: A researcher would like to conduct a hypothesis test to compare the mean SAT scores of students who ... (Read 77 times)

armygirl · **on:** Jul 25, 2018

A researcher would like to conduct a hypothesis test to compare the mean SAT scores of students who have received extra coaching and the mean SAT score of students who have not received extra coaching.

In this case, a paired t-test would be appropriate since a natural pairing exists (a pair consists of a student before coaching and the same student after coaching). If the researcher instead uses independent samples and a pooled or nonpooled t-test, how is this likely to affect the probability of a Type II error?
A) Using independent samples, the probability of a Type II error is likely to be smaller than if a paired sample is used.
B) Using independent samples, the probability of a Type II error is likely to be larger than if a paired sample is used.
C) Using independent samples, the probability of a Type II error is likely to be the same as if a paired sample were used.

Question 2

A herpetologist performed a study on the effects of the body type and mating call of the male bullfrog as signals of quality to mates.

Four life-sized dummies of male bullfrogs and two sound recordings provided a tool for testing female response to the unfamiliar frogs whose bodies varied by size (large or small) and color (dark or light) and whose mating calls varied by pitch (high, normal, or low). The female bullfrogs were observed to see whether they approached each of the four life-sized dummies. Identify the experimental units.
A) All of the frogs, male and female B) The female bullfrogs
C) The male bullfrogs D) The scientist