Question 5:

Positive personality qualities tend to increase the physical attractiveness of a person. A researcher is interested to know whethernegative personality qualities similarlydecrease the physical attraction of a person. The researcher uses a target photograph that has been used many times in previous studies of attractiveness. On a scale ranging from 0 (minimum attractiveness) to 400 (maximum attractiveness), the target photograph has a mean rating of 200 and a standard deviation of 48. Participants are told that the person depicted in the photo has a number of negative personality traits (unkind, cold, lacks a sense of humour, low intelligence) and are then asked to rate the target's physical attractiveness. The 64 participants gave the face an average rating of 180 with a standard deviation of 44.

a) Does this sample indicate a significant change in the attractiveness of the target face? Use a directional hypothesis with = .05.

Step 1: Hypotheses:

Step 2: Decision Criterion:

Step 3: Obtain a Statistic

Step 4: Make a Decision:

Step 5: Report the Result:

b) Report and interpret the effect size studied in the investigation.

c) Report and interpret power for this study. Be sure to include a drawing of the distributions with power shaded appropriately.

d) Construct and interpret the 80% confidence interval for this example.