Confounding often defeats attempts to show one variable causes changes in another variable. Confounding means that:    a) the effects of two or more variables are mixed up, so we cannot say which is causing the response.            b) we don’t know which is the response variable and which is the explanatory variable.            c) we would get widely varied results if we repeated the study many times.            d) we have scheduled too many treatments for the number of subjects we have.

a. Using the results above, can we consider team popularity as a significant mediator and moderator? Justify your answer. b. Is the assumption of the sports psychologist correct when he claimed years of coaching do not have direct effects to team success? Why or why not? c. In the moderation analysis, what happened to the correlations between years of coaching and team success along different levels of team popularity?

Consider that the results of a research study conclude that the “effect of social media use on anxiety depends on gender.” Which statement below is correct based on this conclusion?     a. The research study uncovered a main effect of social media use, but no main effect of gender or interaction between gender and social media use.   b. The research study uncovered a main effect of gender and interaction of gender and social media use, but not main effect of social media use.   c. The research study uncovered an interaction between social media use and gender, but no main effects.   d. The research study uncovered no main effects of gender or social media use, as well as no interaction between gender and social media use.

For a variety of reasons, self-reported disease outcomes are frequently used without verification in epidemiologic research. In a study by Parikh-Patel et al. (A-12), researchers looked at the relationship between self-reported cancer cases and actual cases. They used the self-reported cancer data from a California Teachers Study and validated the cancer cases by using the California Cancer Registry data. The following table reports their findings for breast cancer: Cancer Reported (A) Yes No Total Cancer in Registry (B) 2991 112 3103 Cancer Not in Registry 2244 115849 118093 Total 5235 115961 121196 10. 11. Source: Arti Parikh-Patel, Mark Allen, William E. Wright, and the California Teachers Study Steering Committee, “Validation of Self-reported Cancers in the California Teachers Study,” American Journal of Epidemiology, 157 (2003), 539–545.   (d)  FindðAjBÞ (e)  Find PðB j AÞ (f)  Find the sensitivity of using self-reported breast cancer as a predictor of actual…