A researcher tested a research hypothesis that people withdiagnosed depression will have REDUCED level of depressive symptomsafter a cognitive therapy treatment, as compared to thepre-treatment level of depressive symptoms. The cutoff tvalue is -1.833 for this one-tailed test. The data analysis yieldeda mean change score (post-treatment minus pre-treatment) of -2.5.If the standard error is 2.0, what is the t statistic andwhat is the conclusion of the hypothesis test?
| -2.5; fail to reject the null hypothesis |
| -1.25; reject the null hypothesis |
| -1.25; fail to reject the null hypothesis |
| -2.5; reject the null hypothesis |
A researcher conducts a t test for dependent means(paired-samples t test) with 16 participants. The estimatedpopulation variance of the change scores is 9. What is the standarderror?
In a small-scale trial (sample size = 9) of a psychotherapytreatment for depression, participants were assessed with adepression scale when they entered the trial and again when theyhave completed the 6-month trial. The data yielded a meandifference (change) score of 1.5 and the standard deviation of thesampling distribution was .6. What was the the tstatistic?
In a high school math class, there are 13 male students and 17female students. After all the students have taken the ACT test,the math teacher would like to know if there is a significantdifference in the math component score between the male and femalestudents. If he uses an alpha level of .05 for a two-tailed test,what would be the critical t value for his statisticaltest?
