The Boston Globe (“College Graduation Rates below National Average”) examined the graduation rates at community colleges in Massachusetts. Overall, 16.4% of full-time community college students in Massachusetts earn a degree or certificate within three years. This appears to be well below the national average of 24.7%. To determine this, random samples were taken in both Massachusetts and in the nation as a whole. A file titled Masspass contains outcomes of this sampling. Assume the populations have normal distributions.
a. Determine if there is a difference in the variances of the percentage of community college students who earn a degree or certificate within three years in both Massachusetts and in the rest of the nation. Use a significance level of 0.05.
b. On the basis of the results of part a, select the appropriate procedure to determine if there is a significant difference between the average graduation rates for Massachusetts and for the remainder of the nation.