Professor Liu wants to study whether learning statistics has advanced people's reasoning and logic skills. To do so, he randomly picked three groups of students, each consisting of 35 students. Group 1 students have not taken any statistics course, Group 2 students have taken only DS 301, and Group 3 students have taken both DS 301 and DS 302. Then Professor Liu tested all three groups of students with a set of logic questions. For the test results, an ANOVA test was conducted. It is found that SST = 1,543.1 and SSA = 687.8. What is the value of the MSW (mean square within)