To examine whether mathematics skills of the average high school graduate in urban areas of the United States have declined over the past 10 years, the average scores on the math section of the SAT Reasoning Test (MSAT) were compared for a random sample of five big-city high schools for the years 2002, 2007, and 2012. The results are shown in the following table and accompanying computer output.

a. Determine the sample means for each year.
b. Comment on the independence assumption required for using one-way ANOVA on the data given.
c. Determine the one-way ANOVA table for these data.
d. Test by means of a one-way ANOVA whether any significant differences exist among the three MSAT average scores for the years 2002, 2007, and 2012.
e. Use Scheffe's method to locate any significant differences between pairs of means. (Use α = .05.)