A random sample of 30 executives from companies with assets over $1 million was selected and asked for their annual income and level of education. The ANOVA comparing the average income among three levels of education rejected the null hypothesis. The Mean Square Error (MSE) was 243.7. The following table summarized the results:

High School or Less Undergraduate Degree Master's Degree or More

Number Sampled 7 11 12

Mean Salary (1,000s) 49 76.3 78.3

When comparing the mean annual incomes for executives with undergraduate and master's degrees ormore, the following 95% confidence interval can be constructed:

Select one:

a. 2.0 2.052 * 6.52

b. 2.0 3.182 * 6.52

c. 2.0 2.052 * 42.46

d. 2.0 3.182 * 42.46