For the research scenarios in parts (a) and (b), explain whether a randomized experiment could be used.
a. To compare two programs to reduce the number of commuters who drive to work: providing discount coupons for the bus, or providing shuttle service for people who need to run errands during the workday.
b. To study the relationship between age and opinion about whether marijuana should be legal.
c. For each of parts (a) and (b) of this exercise, state the explanatory variable and the response variable.
d. For each of parts (a) and (b) of this exercise, give an explanation of a possible confounding variable that could be present if an observational study were done.