Question

A random sample of 30 female 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 56.92. The following table summarized the results:

	High School or less	Undergraduate	Master’s or more
Sampled number	11	10	9
Salary (000s)	37	36.5	43.5

a. To compare the mean annual incomes of female executives with an undergraduate degree and female executives with a Master's degree or more, compute the 96% confidence interval. Is there a difference? Why?

b. To compare the mean annual incomes of female executives with a high school education or less and female executives with undergraduate degree, compute the 98% confidence interval. Is there a difference? Why?

c. To compare the mean annual incomes of female executives with a Master’s degree and female executives with a high school or less, compute the 92% confidence interval. Is there a difference? Why?

Answer 1