Question 1

Power for a t test for dependent means can be determined using a power software package, Internet power calculator, or power table. (True or False)

Accepted Answer

Power for a t test for dependent means can be determined using power software packages, Internet power calculators, or power tables.

Question 2

Research articles usually describe t tests in a standard format that includes __________ , __________ , and __________.

Accepted Answer

The answer of Research articles usually describe t tests in...

Question 3

An industrial researcher is a consultant to a large chain of bookstores. Industry reports show that for book stores in general, the average number of complaints received by management for a 1-month period at this time of year is 6.5 (the variance is not known). Seven of this chain's stores are randomly selected to keep records of complaints received over a 1-month period. The numbers of complaints are 4, 8, 9, 0, 3, 5, and 6. Does this chain get a different amount of complaints than book stores in general? (Use the .05 level).
a. Use the five steps of hypothesis gathering.
b. Explain what you did to a person who is familiar with hypothesis testing with a known population variance and a single sample, including understanding decision errors, effect size, and power, but knows nothing about t tests of any kind.

Accepted Answer

The answer of An industrial researcher is a consultant to...

Question 4

When the results of a t test are presented in research articles, the __________ directly follow(s)the "t" and are in parentheses.

Accepted Answer

The answer of When the results of a t test...

Question 5

When results of t tests are presented in a table, __________ will often be used to indicate level of significance.

Accepted Answer

The answer of When results of t tests are presented...

Question 6

Why do repeated-measures designs have so much power?

Accepted Answer

The answer of Why do repeated-measures designs have so much...

Question 7

An organizational specialist is hired as a consultant to a company planning to open a coffee house for college students. The company wants to know if the customers will drink more coffee if the coffee house is decorated in a Paris motif or in a San Francisco motif. To test this, the researcher sets up two similar rooms, but with the two different motifs. She then arranges to have eight students spend an afternoon in each room while being allowed to drink all the coffee they like. (The order in which they sit in the rooms is rotated, so that half do their first afternoon in the Paris room and half in the San Francisco room.)The amount each student drinks is recorded below:
Cups of Coffee Consumed for each Motif
  Is there is' a significant difference between the number of cups of coffee consumed in the two rooms?
a. Use the five steps of hypothesis testing (at the .05 level of significance)
b. Figure the effect size and find the approximate power of this study

Accepted Answer

The answer of An organizational specialist is hired as a...

Question 8

From the statement "t(32)= 2.80, p < .01," the number of people in the sample is assumed to be __________.

Accepted Answer

The answer of From the statement "t(32)= 2.80, p <...

Question 9

It is known that a particular laboratory task takes the average person 2.5 seconds. A researcher was interested in whether older people are slower (take longer)on this task. The researcher tested 30 randomly selected 80-year-olds. Their mean time was 2.7 seconds, with an estimated population standard deviation of 1.4 seconds. What should the researcher conclude (use the .05 level)?
a. Use the five steps of hypothesis gathering.
b. Sketch the distributions involved.
c. Explain what you did to a person who is familiar with hypothesis testing with a known population variance and a single sample, including understanding decision errors, effect size, and power, but knows nothing about t tests of any kind.

Accepted Answer

The answer of It is known that a particular laboratory...

Question 10

A researcher administered a scale measuring concern for farm workers (high scores mean high concern)to seven students before and after they attended a film about union organization of farm workers. Results are shown below.
Scores on the Concern Measure, Before and After Film
  Do these results support the hypothesis that the film affected concern for the lives of farm workers? (Use the .05 level.)
a. Use the five steps of hypothesis testing
b. Figure the effect size and find the approximate power of this study.

Accepted Answer

The answer of A researcher administered a scale measuring concern...

Question 11

A consumer researcher was asked to test a claim by a franchise swimming instruction program. Specifically, they claimed that they could teach the average 7-year-old to swim across an Olympic-size pool in less than 2 hours. The researcher arranged for eight randomly selected 7-year-old children to take instruction at this school and kept a careful record of how long it took each child. The times (in minutes)were 60, 120, 110, 80, 70, 90, 100, and 130. What should the researcher conclude? Carry out a t test for a single sample (120 minutes is the "known" population mean)using the .01 significance level.
a. Use the five steps of hypothesis testing.
b. Explain what you did to a person who is familiar with hypothesis testing with a known population variance and a single sample, including understanding decision errors, effect size and power but knows nothing about t tests of any kind. Be sure to explain how this problem differs from a problem with a known population variance and a single sample.

Accepted Answer

The answer of A consumer researcher was asked to test...

Question 12

Provide an example of a study that would utilize a t test for a single sample. List three differences in how you would carry out hypothesis testing for a t test for a single sample versus for a Z test.

Accepted Answer

The answer of Provide an example of a study that...

Question 13

There are specially constructed tables that provide the approximate number of participants needed to achieve __________ power for a planned study involving a t test.

Accepted Answer

The answer of There are specially constructed tables that provide...

Question 14

A researcher working at a particular company wants to know if workers' health would improve if they were given extra days 'off. In this company, all workers undergo a standard physical exam twice a year and after each exam an overall health rating (higher scores mean better health)is automatically provided to the company. To conduct the study, the researcher selected five workers at random. She then arranged to have these five workers receive an additional 2 days off every month over the period between health exams. She then compared the health scores on the two exams. Do the results shown in the table below support the notion that extra days off improves health? (Use the .05 level.)
a. Use the five steps of hypothesis testing
b. Figure the effect size and find the approximate power of this study.
c. Explain your results.
Health Rating, Before and After Period of Extra Days Off
Worker Before After
A 75 81
B 66 67
C 44 46
D 86 88
E 89 89

Accepted Answer

The answer of A researcher working at a particular company...

Question 15

A study tested the effects of science fiction movies on people's belief in the supernatural. A scale was designed to measure the degree that a person believes in the supernatural (high scores indicate high levels of belief). Seven participants completed the scale before and after watching a popular science fiction movie. Participants' scores are listed below. Assume that the researcher had reason to expect participants to believe less in the supernatural after watching the movie.
Belief-in-Supernatural Scores, Before and After Watching Science Fiction Movie
  Carry out a t test for dependent means (using the .01 significance level).
a. Use the five steps of hypothesis testing.
b. Figure the effect size and find the approximate power of this study.

Accepted Answer

The answer of A study tested the effects of science...

Quiz 8: Introduction to the T Test: Single Sample and Dependent Means