A Pew Research Center survey of 2002 U.S. adults in August 2014 and a survey of 3748 scientists connected to the American Association for the Advancement of Science (AAAS) in September 2014 both asked the following question: "Do you favor or oppose the increased use of fracking?" In the Pew Research Center survey, fracking was favored by 37%, whereas in the survey of scientists, it was favored by 31%. Both surveys used random samples.
a. Identify the response variable and the explanatory variable.
b. To conduct inference, should we treat the sample of U.S. adults and the sample of scientists from the AAAS as dependent or as independent? Explain.

c. The AAAS survey also asked each of the 3748 scientists whether they favor or oppose more offshore oil and gas drilling. Thirty-two percent responded that they favor it. To compare this to the percentage who favored fracking, should you treat the samples as dependent or as independent? Why?