Refer to Exercise 14.129. A similar study determined the monthly household income of households headed by 25- to 34-year-olds with only a high school diploma. The incomes were converted to 2012 dollars.

a. Is there sufficient evidence to infer that household incomes differed for 25- to 34-year-olds with high school diplomas between the three periods?

b. Are the required conditions satisfied? Explain.

In exercise 14.129

How have 25- to 34-year-olds with university degrees fared financially since 1984? To answer this question, the Pew Research Center conducted surveys in 1984, 1996, and 2009 recording monthly earnings for graduates with three different types of degrees. The incomes were converted into 2012 dollars.