My Research Methods class (N = 14) was interested in whetherstudying alone or in groups would result in better grades on theirthird exam. Half of the class (n = 7) studied for the exam alone,while the other half (n = 7) studied as a group. Their grades aresummarized in the below tables:
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Study Alone |
Student | Grade |
1 | 78% |
2 | 97% |
3 | 79% |
4 | 90% |
5 | 91% |
6 | 74% |
7 | 72% |
Study in Group |
Student | Grade |
8 8 | 72% |
9. 9 | 89% |
1 10 | 77% |
1 11 | 87% |
1 12 | 89% |
1 13 | 77% |
1 14 | 69% |
Using the above data, answer the following questions
- Which type of t-test (one-sample, independent samples, relatedsamples) is appropriate for determining if those that that studiedin a group earned better or worse grades than those who studiedalone? Why?
- State the alternative and null hypotheses (using thestatistical notation for stating mathematical relationships) thatrepresents the prediction that those who studied in a group willobtain grades that are, on average, different from that of thosewho studied alone.
- Calculate pooled variance, standard error of the difference,and tobt.
- Using an alpha of 0.05, what is tcrit?Would you reject or fail to reject the null hypothesis? Why?
