multiple choice

Question 1 of 25 1.0 Points

The __________ is a hypothesis-testing procedure used when a sample mean is being compared to a known population mean and the population variance is unknown.

 A.ANOVA 

 B.t test for a single sample 

 C.t test for multiple samples 

 D.Z test 

Question 2 of 25 1.0 Points

In the formula for estimating the population variance from the scores in a sample, the sum of squared deviations is divided by:

 A.the number of participants in the sample 

 B.the number of participants in the sample minus one 

 C.the number of participants in the population 

 D.the number of participants in the population minus one 

Question 3 of 25 1.0 Points

Which of the following is TRUE about t distributions?

 A.There are exactly 10 categories of t distributions. 

 B.For any given sample size, there are between two and N-1 appropriate t distributions. 

 C.The larger the sample size, the more a t distribution resembles a normal curve. 

 D.t distributions are generally bimodal. 

Question 4 of 25 1.0 Points

The variance of a sample is said to be “biased” because it consistently __________ the actual variance of the population.

 A.overestimates 

 B.underestimates 

 C.enlarges 

 D.divides 

Question 5 of 25 1.0 Points

A local newspaper reports that young women in your town (i.e., a known population) sleep an average of only 5 hours per night. However, you think that women in your town who are enrolled at your college sleep more than that. You randomly select 200 women from your college and ask them to accurately record their hours of sleep. You find that they sleep an average of 7 hours per night. What test would you use to determine whether this mean difference is statistically meaningful?

 A.ANOVA 

 B.t test for dependent means 

 C.t test for a single sample 

 D.regression 

Question 6 of 25 1.0 Points

What is the main difference between Z score and t score?

 A.t scores are used when the study requires a one-tailed test 

 B.t scores are used when the population variance is unknown 

 C.t scores are used whenever the sample size is greater than 30 

 D.t scores are only used when inferences are made about other samples 

Question 7 of 25 1.0 Points

The shape of a t distribution:

 A.is typically bimodal 

 B.is typically rectangular 

 C.will vary according to the mean of the population you used to estimate sample variance 

 D.will vary according to the degrees of freedom in the sample you used to estimate population variance 

Question 8 of 25 1.0 Points

The t score is your sample’s mean minus the __________ divided by the __________.

 A.sample size; variance of the distribution of means 

 B.sample size minus 1; standard deviation of the distribution of means 

 C.population mean; standard deviation of the distribution of means 

 D.population median; variance of the distribution of means 

Question 9 of 25 1.0 Points

Difference scores are usually used with:

 A.a t test for a single sample 

 B.a t test for dependent means 

 C.a t test for independent means 

 D.all of the above 

Question 10 of 25 1.0 Points

Other names for the t test for dependent means include all of the following EXCEPT:

 A.paired-sample t test 

 B.t test for matched samples 

 C.t test for matched pairs 

 D.independent-sample t test 

Question 11 of 25 1.0 Points

The difference between a person’s score on one testing and the same person’s score on another testing:

 A.test score 

 B.deleted score 

 C.distance score 

 D.difference score 

Question 12 of 25 1.0 Points

Suppose a researcher conducted a t test for dependent means using scores from pairs of research participants (i.e., mothers and sons). The researcher considered each pair as if it were one person and calculated a difference score for each pair. In this example, the t test could also be called a:

 A.t test for matched pairs 

 B.t test for unmatched pairs 

 C.t test for mixed pairs 

 D.t test for independent pairs 

Question 13 of 25 1.0 Points

Which of the following is an assumption or requirement within the logic and mathematics of the t test?

 A.A sample of more than 50 people 

 B.A normal population 

 C.A normal sample 

 D.A mean change score that is greater than 10 

Question 14 of 25 1.0 Points

The estimated effect size for a study using a t test for dependent means is the mean of the difference scores divided by the:

 A.difference scores 

 B.estimated variance of the sample of difference scores 

 C.estimated standard deviation of the population of difference scores 

 D.estimated mean of the population of difference scores 

Question 15 of 25 1.0 Points

What is considered a medium effect size for a t test for dependent means?

 A..20 

 B..30 

 C..50 

 D..80 

Question 16 of 25 1.0 Points

Which of the following is an assumption for the t test for dependent means?

 A.The population variance is known. 

 B.The population mean is greater than the sample mean. 

 C.The population follows a normal distribution. 

 D.The sample follows a normal distribution. 

Question 17 of 25 1.0 Points

For a research study that utilized a t test for dependent means, an effect size of .98 would be considered:

 A.small 

 B.medium 

 C.large 

 D.very large 

Question 18 of 25 1.0 Points

Power for a t test for dependent means can be determined using:

 A.a power software package 

 B.an Internet power calculator 

 C.a power table 

 D.any of the above 

Question 19 of 25 1.0 Points

When utilizing t tests, __________ would be considered an adequate amount of power.

 A.40% 

 B.50% 

 C.65% 

 D.80% 

Question 20 of 25 1.0 Points

What is often a limitation of research using a repeated-measure design?

 A.low power 

 B.lack of control group 

 C.low standard deviation of difference scores 

 D.all of the above 

Question 21 of 25 1.0 Points

What type of research design would be expected to yield the highest amount of power (assuming studies with the same sample size)?

 A.A study using a Z test 

 B.A study using a t test 

 C.A study using a single-sample design 

 D.A study using a repeated-measures design 

Question 22 of 25 1.0 Points

Approximately how many research participants would be required for 80% power for a study using the t test for dependent means (assume a one-tailed hypothesis with an expected medium effect size of .50):

 A.12 

 B.26 

 C.33 

 D.196 

Question 23 of 25 1.0 Points

Approximately how many research participants would be required for 80% power for a study using the t test for dependent means (assume a two-tailed hypothesis with an expected small effect size of .20):

 A.156 

 B.196 

 C.26 

 D.33 

Question 24 of 25 1.0 Points

What is the approximate power for a study using the t test for dependent means with an expected large effect size, one-tailed and N = 50? Answer: D

 A.40 

 B.77 

 C.88 

 D.nearly 1 

Question 25 of 25 1.0 Points

If not otherwise indicated, one should assume that researchers utilized a __________ test. Answer: B

 A.one-tailed 

 B.two-tailed 

 C.whole sample 

 D.partial sample