When the General Social Survey most recently asked subjects whether they are a member of an environmental group (variable GRNGROUP) and whether they would be very willing to pay higher prices to protect the environment (variable GRNPRICE), the results were as shown in the table. For a randomly selected American adult:
a. Estimate the probability of being (i) a member of an environmental group and (ii) willing to pay higher prices to protect the environment.
b. Estimate the probability of being both a member of an environmental group and very willing to pay higher prices to protect the environment.
c. Given the probabilities in part a, show that the probability in part b is larger than it would be if the variables were independent. Interpret.
d. Estimate the probability that a person is a member of an environmental group or very willing to pay higher prices to protect the environment. Do this