Please answer the "Factual Questions" attached along with the information attached.

STATISTICAL GUIDE The standard deviation (SD) gives a numerical value for the amount of variability or spread in a distribution. If a distribution is normal, the standard deviation can be used to gain a lot of To review mean, see information about a distribution quickly: Exercise 2.1. To review standard deviation, see 68% of scores are within 1 SD of the mean of the distribution Exercise 2.4. To review 95% of scores are within 1.96 SDs of the mean of the distribution normal distribution, see 99% of scores are within 2.58 SDs of the mean of the distribution Exercise 3.8 99.7% of scores are within 3 SDs of the mean of the distribution. Since 1.96 SDs is very close to 2 SDs, researchers often use 2 SDs as a benchmark. Researchers will say that 2 SDs from the mean captures approximately 95% of the scores in a distribution (even when 2 SD actually capture a little more than that). BACKGROUND NOTE The study below investigated alcohol education for incoming college freshman. The researchers investigated if the timing of the education had an impact-during the summer before college vs. during the first year of college. The intervention group completed the alcohol education during the summer, and the control group completed the alcohol education during their freshman year. 5.38 38 EXCERPT FROM THE RESEARCH ARTICLE? The authors assessed the short-term effectiveness of a Web-based alcohol education program on entering freshmen. Study participants were incoming first-year students at a midsized, rural, elite, private university in the Northeast. In June of 2006, all incoming first-year students were randomly assigned to either an intervention. or control . . . group . . . In mid-July, students in the intervention and control groups received a letter, mailed to their home address, detailing the expectations for completing the online program. Both groups also received printed materials highlighting the university's alcohol policy. Students in the intervention group were expected to complete the precourseEXCERPT FROM THE RESEARCH ARTICLE1 The authors assessed the short-term effectiveness of a Web-based alcohol education program on entering freshmen. Study participants were incoming first-year students at a midsized, rural, elite, private university in the Northeast. . . In June of 2006, all incoming first-year students were randomly assigned to either an intervention. . . or control . . . group . . . In mid-July, students in the intervention and control groups received a letter, mailed to their home address, detailing the expectations for completing the online program. Both groups also received printed materials highlighting the university's alcohol policy. Students in the intervention group were expected to complete the precourse knowledge test. . . . the Web-based course, and the postcourse examination prior to arrival on campus. The control group participants were expected to complete only the precourse knowledge test and the precourse survey prior to coming to campus. . . . The control group was . . . invited to complete the online course during the academic year. Table 1 Pre- and Postintervention Knowledge Test Scores Control group test Intervention group test scores scores Pre Post Pre Post n M SD M SD M SD M SD All student 1,891 73.3 9.9 83.2 12.8 74.0 8.7 88.4 6.2 participants STUDY QUESTIONS Factual Questions v higher pretest scores, on average?STUDY QUESTIONS Factual Questions 1. Just by visual inspection, which group had slightly higher pretest scores, on average? 2. On the pretest, which group had greater variability in their scores? 3. On the posttest, which group had less variability in their scores? 4. Just by visual inspection, which group showed a greater gain from pretest to posttest, on average? 5. Assuming that the distribution of pretest scores for the control group is normal, between what two values are the middle 95% of participants (approximately)? 6. Does the mean pretest score for the intervention group fall within the range of the two scores that you gave as your answer to Question 5? p.39 39 7. Assuming that the distribution of posttest scores for the control group is normal, between what two values are the middle 95% of participants (approximately)? B. Assuming that the distribution of posttest scores for the control group is normal, between what two values are the middle 99.7% of participants? 9. Assuming that the distribution of pretest scores for the control group is normal, between what two values are the middle 99.7% of participants? 10. Assuming a normal distribution of the pretest intervention group scores, what percentage of the participants had a pretest score between 56.6 and 91.4? Questions for Discussion 11. If your work is correct, the interval you calculated for Question 8 should be larger than the interval you calculated for Question 7. Does this make sense? Explain. 12 In addition to increases in knowledge, what other outcomes might a researcher consider in a study of an alcohol intervention program for college students? 13. Would you be willing to generalize the results of this study at a private university to public universities? Explain. NOTE ico, (2008). Impact of an online