14.31 Income by gender and degree In 2012, the population mean hourly wage for males was $17 for high school graduates,

$33 for college graduates and $43 for males with more advanced degrees. For females, the means were $14 for high school graduates, $24 for college graduates, and

$32 for females with more advanced degrees.3

a. Identify the response variable and the two factors.

b. Show these means in a two-way classification of the two factors, similar to the table in the margin of Example 9.

c. Compare the differences between males and females for (i) high school graduates and (ii) college graduates.

Explain why there is interaction and describe it.

d. Show a set of six population mean wages that would satisfy H0: no interaction.