2.44 Income and gender:  The relative frequency table below displays the distribution of annual total personal income (in 2009 inflation-adjusted dollars) for a representative sample of 96,420,486 Americans. These data come from the American Community Survey for 2005-2009. This sample is comprised of 59% males and 41% females.

IncomeTotal Percentage
$1 to $9,999 or loss2.2%
$10,000 to $14,9994.7%
$15,000 to $24,99915.8%
$25,000 to $34,99918.3%
$35,000 to $49,99921.2%
$50,000 to $64,99913.9%
$65,000 to $74,9995.8%
$75,000 to $99,9998.4%
$100,000 or more9.7%


a) Describe the distribution of total personal income:

b) What is the probability that a randomly chosen US resident makes less than $50,000 per year? % (please round to two decimal places, ie. xx.xx%)
c) What is the probability that a randomly chosen US resident makes less than $50,000 per year and is female? % (please round to two decimal places, ie. xx.xx%)
d) The same data source indicates that 71.8% of females make less than $50,000 per year. What could explain the discrepancy between this number and the number you calculated in part c)?