There are many factors that affect a student’s success in school. A professor is concerned that many of her students work at part-time or even full-time jobs while they are attending school. Work responsibilities leave less time available for studying. The professor selects a random sample of her students (her classes are quite large) and organizes the data according to how many hours per week each student works, on average. She then records the final marks for the Microeconomics course these students have just completed. The data are available in MyStatLab. Is there evidence, at a 5% significance level, of an association between marks and the number of hours worked per week? That is, are the mean marks equal? If there are differences in the average marks, discuss what those differences are.