Independent Samples 1' Test A teacher wants to know whether students learn more from lecture or discussion. Using her two classes, she creates two independent research groups: Group 1 receives only lecture- based instruction and Group 2 receives only discussionbased instruction. After the two classes take Exam 1. the teacher compares the groups' scores. Using a = .05 and a two-tailed hypothesis, run an independent samples I test to compare the scores. Points are noted in red [but and brackets I I. Group I [lecture-based instruction)(iroup 2 {discussionbasal instruction) n 8 n ' 8 r )-' r )1 7'5 74 77 75 XI 83 85 77 7'6 77 85 X4 87 1. Write H. and H\": [+2] 2. Calculate the two means (and ). [+2] 3. Subtract the group mean from each raw score and square the difference. [+4] 4. Add together the squared differences to nd the sum of squares (SS) for each group. [+4] 5. Calculate the combined variance between the two groups (szlmulul). [+6l 6. Calculate the standard deviation of minus . [+6] 7. Calculate t [+4] 8. Calculate the degrees of freedom (dj). [+4] 9. Report the calculate t value along with the dfl [+3] r( )= 10. Locate t'.,,,,...,,ill distribution and identify the regions of rejection and retention. [+5] I]. Make a statistical decision and form a conclusion: [+10]