# B which is the explanatory variable and which is the

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(b) Which is the explanatory variable and which is the response variable?
(c) According to the second sentence, does there appear to be an association between the variables?
(d) Use the first sentence to determine whether the university president is assuming a causal relationship between the variables.
Solution
Yes, the president is assuming that there is a causal relationship, since he states that “single sex dorms reduce the number of student hook-ups”. (e) Use the second sentence to determine whether the cited studies appear to be observational studies or experiments?
Solution There is no indication that any variable was manipulated, so the studies are probably observational studies. (f) Name a confounding variable that might be influencing the association. ( Hint: Students usually request one type of dorm or the other.) Students self-select the type of dorm Solution The type of student who requests a single sex dorm might be different from the type of student who requests a co-ed dorm. There are other possible confounding variables. (g) Can we conclude from the information in the studies that single-sex dorms reduce the number of student hook-ups? No! Solution No! We should not assume causation from an observational study. (h)
What common mistake is the university president making?
Does Red Increase Men's Attraction to Women? A recent study 45 examined the impact of the color red on how attractive men perceive women to be. In the study, men were randomly divided into two groups and were asked to rate the attractiveness of women on a scale of 1 (not at all attractive) to 9 (extremely attractive). One group of men were shown pictures of women on a white background and the other group were shown the same pictures of women on a red background. The men who saw women on the red background rated them as more attractive. All participants and those showing the pictures and collecting the data were not aware of the purpose of the study. (a) Is this an experiment or an observational study? Explain.