For the following four questions, use the appropriate formula and your t-Test table in Appendix B2. Use the following study set-up:

A researcher is interested in seeing if negative political ads against an opponent (group one) are more persuasive than positive ads for an original candidate (group two). She creates a scale to measure how persuasive the ads are; larger numbers mean more persuasive.

She collects the following data (put these numbers down; they don't appear on the followup questions):

• Group One (Negative ads): x1= 7.3, s12= 2.64, n₁ = 20
• Group Two (Positive ads):x2= 9.36, s22= 4.8, n₂ = 20

9. What is the t-statistic for this test?

(put your answer below, to two decimal places as a positive value; sign doesn't matter)

10. What is your degrees of freedom for this data set?

a. 20

b. 19

c. 40

d. 38

e. None of the above

11. What is the standard deviation for group two?

a. 2.40

b. 3.65

c. 2.19

d. 4.8

e. None of the above

12. What can be said about the significance of the study?

a. The t obtained value exceeds the critical value at the p < 0.05 level but not the p < 0.01 level

b. The t obtained value exceeds the critical value at the p < 0.05 level and the p < 0.01 level

c. The t obtained value does not exceed either the critical value at the p < 0.05 level or the p < 0.01 level

d. The t obtained value exceeds the critical value at the p < 0.01 level but not the p < 0.05 level

e. None of the above

13. What should you interpret based on the effect size of Ad Types on Persuasion?

a. Ad type has a strong persuasive effect.

b. Ad type has a moderate persuasive effect.

c. Ad type has a small persuasive effect.

d. Ad type has no effect on persuasion.