1. Sample Presentation

2. Research Question Do students who enjoy taking risks study more than students who do not? Do students who enjoy taking risks study more than students who do not? Specifically, how do these two groups compare on the average number of hours spent studying in a typical week? Specifically, how do these two groups compare on the average number of hours spent studying in a typical week?

3. Variables used I used H13: Do you enjoy taking risks? to form two groups. I used H13: Do you enjoy taking risks? to form two groups. I used A9: How many total hours do you study typically study Monday through Friday? as a quantitative variable. I used A9: How many total hours do you study typically study Monday through Friday? as a quantitative variable.

4. Hours studied by students who do enjoy taking risks

5. Students who enjoy taking risks 35 people in the sample enjoy taking risks. 35 people in the sample enjoy taking risks. The average number of hours they study in a typical week is 19.9 hours, with a standard deviation of 11.5 hours. The average number of hours they study in a typical week is 19.9 hours, with a standard deviation of 11.5 hours. The histogram is somewhat symmetric. The histogram is somewhat symmetric.

6. Hours studied by students who don’t enjoy taking risks

7. Students who don’t enjoy taking risks 29 people in the sample don’t enjoy taking risks. 29 people in the sample don’t enjoy taking risks. On average they study 16.6 hours in a typical week, with a standard deviation of 11.3 hours. (This is SD+) On average they study 16.6 hours in a typical week, with a standard deviation of 11.3 hours. (This is SD+) The histogram is not symmetric: it has a right tail. The histogram is not symmetric: it has a right tail.

8. Hypothesis testing Null hypothesis: there is no difference between the average number of hours studied in a typical week between students who enjoy taking risks and those who do not enjoy taking risks. Null hypothesis: there is no difference between the average number of hours studied in a typical week between students who enjoy taking risks and those who do not enjoy taking risks. Alternate hypothesis: Students who enjoy taking risks spend more time on studying. Alternate hypothesis: Students who enjoy taking risks spend more time on studying.

9. Calculating SEavg for each group Enjoy risk taking: Enjoy risk taking: SE avg = 11.482/ sqrt(35) = 1.9 hours Don’t enjoy risk taking: Don’t enjoy risk taking: SE avg = 8.7/sqrt(29) = 1.6 hours

10. SE for the difference The SE for the difference between these two averages is The SE for the difference between these two averages is SEdiff = sqrt(1.9 2 + 1.6 2 ) SEdiff = sqrt(1.9 2 + 1.6 2 ) SEdiff = 2.5 hours SEdiff = 2.5 hours

11. 2-sample z-test The difference between the two averages is 11.482 – 11.338 = 0.144 The difference between the two averages is 11.482 – 11.338 = 0.144 The z-value for this difference is The z-value for this difference is 0.144/SEdiff = 0.144/2.5 = 0.06 The area under the normal curve to the right of z = 0.06 is approx (100-4)/2 = 48% P = 48% is much larger than 5% P = 48% is much larger than 5%

12. Conclusion We fail to reject the null hypothesis. There is no statistically significant difference between students who enjoy taking risks and those who don’t enjoy taking risks in the average number of hours of study in a typical week. We fail to reject the null hypothesis. There is no statistically significant difference between students who enjoy taking risks and those who don’t enjoy taking risks in the average number of hours of study in a typical week.