To determine what students at a school would be willing to do to address global warming, researchers take a random sample of 100 students. the students answer the questions, "how high of a tax would you be willing to add to gasoline (per gallon) in order to encourage drivers to drive less or to drive more fuel-efficient cars? " and, "do you believe (yes or no) that global warming is a serious issue that requires immediate action? " the researchers want to compare the mean response on gasoline taxes (the first question) for those who answer yes and for those who answer no to the second question.