The contingency table below provides a joint frequency distribution for a random sample of patients at a hospital classified by blood type and sex. Blood Type $$\begin{array} { | l | c | c | c | c | c | }
\hline \text { Sex } & \text { O } & \text { A } & \text { B } & \text { AB } & \text { Total } \
\hline \text { F } & 103 & 95 & 18 & 9 & 225 \
\hline M & 72 & 69 & 17 & 7 & 165 \
\hline \text { Total } & 175 & 164 & 35 & 16 & 390 \
\hline
\end{array}$$ If a person is selected at random from the sample,find the probability that the person has blood type B.
A)0.577
B)0.080
C)0.090
D)0.514
E)0.046

Question

The contingency table below provides a joint frequency distribution for a random sample of patients at a hospital classified by blood type and sex. Blood Type $$\begin{array} { | l | c | c | c | c | c | } 
\hline \text { Sex } & \text { O } & \text { A } & \text { B } & \text { AB } & \text { Total } \
\hline \text { F } & 103 & 95 & 18 & 9 & 225 \
\hline M & 72 & 69 & 17 & 7 & 165 \
\hline \text { Total } & 175 & 164 & 35 & 16 & 390 \
\hline
\end{array}$$ If a person is selected at random from the sample,find the probability that the person has blood type B.
A)0.577
B)0.080
C)0.090
D)0.514
E)0.046

Quizplus · Accepted Answer

From the contingency table, we see that there are 50 people with blood type B out of a total of 550 people, so the probability of selecting a person with blood type B at random is:

P(B) = 50/550 = 0.090

Therefore, the best choice is C.

The Contingency Table Below Provides a Joint Frequency Distribution for a Random