From which of the following studies can cause and- effect conclusions potentially be drawn? If cause and effect can be determined, explain what may cause what.
a. Subjects were randomly assigned to watch one of two videos, one that was about a sad situation and one that was about a happy situation. The group that watched the sad video scored significantly lower on a quiz about their mood.
b. Students collected data on city residents shopping in their city’s downtown stores and another sample from city residents that were shopping at the mall on the outskirts of the city. They found that those shopping downtown were significantly more likely to vote for the school millage than those shopping at the mall.
c. From a random sample of students, it was found that those who are members of Greek organizations have significantly lower grade point averages.