An admissions officer wanted to know if there was a difference in mean GPA between college sophomores who lived on-campus or off-campus. One-hundred college sophomores who lived on-campus were randomly selected and their GPA's were compared with one hundred different college sophomores who lived off campus. The college sophomores who lived on campus had a mean GPA of 3.27 with a standard deviation of .23, while the college sophomores who lived off campus had a mean GPA of 2.95 with a standard deviation of .29. Which of the 'big five' parameters is this scenario? What is the value of the sample statistic