3. The accompanying table presents data from the U.S. Census Bureau on median and mean income of male workers for the years 1972 and 2012. The income figures are adjusted to eliminate the effect of inflation. Year Median income Mean income (in 2012 dollars) 1972 $36,547 $42,383 2012 33,904 49,915 Source: U.S. Census Bureau.

a. By what percentage has median income changed over this period? By what percentage has mean income changed over this period?

b. Between 1972 and 2012, has the income distribution become less or more unequal? Explain.