Exam 12: The Two-Sample T-Test

The freshmen competed with the sophomores to see who could raise the most money by recycling.The appropriate design for testing the significance of the difference between the means is

You have stated your alternative hypothesis as .If , , , ,and ,what is ?

What is the standard error of the difference?

If is true and we find a difference between our sample means,how would we explain this?

In a related-samples t-test,we use each pair of scores to produce a D value.How is D calculated?

In a study to determine the effectiveness of pain management therapy in persons with chronic pain,20 individuals experiencing chronic pain were selected.Based on each individual's assessment of his or her pain level,each participant in the group that received the therapy was matched with a participant in the group that did not receive the therapy.Descriptive statistics regarding the differences in scores are provided below.Conduct an appropriate two-tailed t-test for using and determine the appropriate outcome.

What are the degrees of freedom for an independent samples t-test that uses two samples with n = 12 in each sample?

If the variance for Sample 1 is 5 and the variance for Sample 2 is 3,where = 10 and = 12,what is ?

The first 10 students who arrived for the Friday lecture filled out a questionnaire on their attitudes toward the instructor.The first 10 who were late for the lecture were spotted,and afterward filled out the same questionnaire.The appropriate design for testing the significance of the difference between the means is

If a researcher predicts that the experimental treatment will produce a decrease in an independent samples t-test ,how will the null hypothesis be stated?

Renee is studying the effect of positive reinforcement for her psychology class.She gets 16 pigeons.These pigeons are from eight egg clutches with two pigeons from each clutch.Renee matches each pigeon in Reinforcement Schedule A with its clutchmate in Reinforcement Schedule B.After training the pigeons,she measures the number of correct responses by each in 10 trials.Using a two-tailed test and ,use the data below to determine whether or not there is a difference between the two schedules.

What are we stating if we reject the null hypothesis in an independent samples t-test?

The assumptions of the t-test for related samples are the same as those for the t-test for independent samples except for requiring

If a researcher predicts that the experimental treatment will produce an increase in an independent samples t-test ,how will the null hypothesis be stated?

What are the degrees of freedom for an independent samples t-test that uses one sample with n = 13 and one sample with n = 15?

Suppose the average reading speed of 15 randomly selected elementary school students is 25,and the average reading speed of 15 randomly selected junior high school students is 31.You compute an independent samples t-test,and your is 3.12,which is statistically significant.Which of the following is the most appropriate conclusion?

When are two samples considered to be related?

In a related-samples t-test,N equals

What does the homogeneity of variance assumption state?

What is the next step in an experiment if the results of an independent samples t-test are statistically significant?