91Ó°ÊÓ

$500\text{married couples were surveyed about their annual earnings.}$

$\text{Probability of an event}=\frac{\text{Number of favorable outcomes}}{\text{Number of total outcomes}}$

$\text{Couples in which the husband earns less than}\$25,000=212+36=248$

The probability that the husband earns less than $ 25,000$=\frac{248}{500}=0.496$

$\text{Couples in which husbands more than}\$25,000=198+54=252$

$\text{Couples in which the wife earns more than}\$25,000\text{given the husband earns more than}\$25,000=54$

$\text{Probability that the wife earns more than}\$25,000\text{given the husband earns more than this amount}$$=\frac{54}{252}=\frac{3}{14}=0.214$

$\text{Couples in which husbands less than}\$25,000=212+36=248$

$\text{Couples in whichthe wife earns more than}\$25,000\text{given the husband earns less than this amount}=36$

$\text{Probability that the wife earns more than}\$25,000\text{given the husband earns less than this amount}$$=\frac{36}{248}=\frac{9}{62}=0.145$