The Centers for Disease Control and Prevention receives information about the causes for HIV/AIDS infection in the United States. Here are the causes of infection and their respective probability among American women age 20 to 24 years:
?
?
$\begin{array}{c}
\begin{array}{lll}
\bf{Cause}\
\text{Injection drug use} \
\text{Heterosexual sex} \
\text{Perinatal infection} \
\text{Other causes}
\end{array}
\begin{array}{lll}
\bf{Probability}\
? \
0.664 \
0.125 \
0.095
\end{array}
\end{array}$ What is the probability that an American woman age 20 to 24 contracted HIV/AIDS either via heterosexual sex or via perinatal infection?

Question

Quizplus · Accepted Answer

The probability of contracting HIV/AIDS either via heterosexual sex or perinatal infection is the sum of the probabilities of these two causes: 0.664 (heterosexual sex) + 0.125 (perinatal infection) = 0.789.

The Centers for Disease Control and Prevention Receives Information About