e. er a 1 S 10.33 Does the media influence your attitude toward tanning Dermatologists' primary recommendation to prevent skin cancer is minimal exposure to the sun. Yet models used in product advertisements are typically well-tanned. Do such advertisements influence a consumer's attitude to ward tanning? University of California and California State University researchers designed an experiment to investi- gate this phenomenon and published their results in Basic and Applied Social Psychology (May 2010). College student participants were randomly assigned to one of three con- ditions: (1) view product advertisements featuring models with a tan, (2) view product advertisements featuring mod- els without a tan, or (3) view products advertised with no ow models (control group). The objective was to determine 20whether the mean attitude toward tanning differs across the three conditions. A tanning attitude index (measured on a scale of 0 to 5 points) was recorded for each participant. The results are summarized in the accompanying table. Sample size Mean Tanned Models Models with No Tan No Models 56 56 56 2.40 2.11 2.50 .73 .82 Standard deviation .85 Source: Mahler, H., et al. "Effects of media images on attitudes toward tanning." Basic and Applied Social Psychology, Vol. 32, No. 2, May 2010 (adapted from Table 1). ST0203 a. Identify the type of experimental design utilized by the researchers. b. Identify the experimental units, dependent variable, and treatments for the design. c. Set up the null hypothesis for a test to compare the treatment means. Quiwall d. The sample means shown in the table are obviously different. Explain why the researchers should not use these means alone to test the hypothesis, part c. e. The researchers conducted an ANOVA on the data and reported the following results: F = 3.60, p-value = .03. Carry out the test, part c. Use a = .05 to draw your conclusion. f. What assumptions are required for the inferences de- rived from the test to be valid? R Code: ANOVA and Simple Linear Regression # This is an example of the ANOVA procedure in R # This code will analyze data from a # Completely Randomized Design (CRD) (sec 10.2) # The data given here are the golf ball distances # from the example we studied in class # I am calling the data set "golfdata". # The factor is brand. # The response variable is dist. golfdata