The accompanying table presents data from the U.S. Census Bureau on median and mean income of male workers for the years 1972 and 2009. The income figures are adjusted to eliminate the effect of inflation.

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 2009, has the income distribution become less or more unequal? Explain.

Year Median income Mean income (in 2009 dollars) $42,617 32,184 $47,708 46,806 1972 2009