A sociologists was investigating the ages of grandparents of high school students. From a random sample of 10high school students, the sociologist collected data on the current ages, in years, of the students’ maternal grandparents. a. One of the sociologist’s research questions was about the mean difference in age without regard to which grandparent is older. The interval constructed in part (a) does not address such a question. Based on the sample of high school students, give the value of the point estimate for the mean difference in age that could be used to address the sociologist’s question.