The following contingency table provides a joint frequency distribution for a group of retired people by career and age at retirement. Age at Retirement $$\begin{array} { | c | c | c | c | c | c | }
\hline \text { Career } & 50 - 55 & 56 - 60 & 61 - 65 & \text { Over 65 } & \text { Total } \
\hline \text { Attorney } & 8 & 41 & 87 & 36 & 172 \
\hline \begin{array} { c }
\text { College } \
\text { Professor }
\end{array} & 10 & 38 & 71 & 31 & 150 \
\hline \text { Secretary } & 21 & 45 & 63 & 49 & 178 \
\hline \text { Store Clerk } & 18 & 44 & 70 & 50 & 182 \
\hline \text { Total } & 57 & 168 & 291 & 166 & 682 \
\hline
\end{array}$$ Suppose one of these people is selected at random.Compute the probability that the person selected was a store clerk.
A)0.084
B)0.099
C)0.316
D)0.267
E)0.026

Question

The following contingency table provides a joint frequency distribution for a group of retired people by career and age at retirement. Age at Retirement $$\begin{array} { | c | c | c | c | c | c | } 
\hline \text { Career } & 50 - 55 & 56 - 60 & 61 - 65 & \text { Over 65 } & \text { Total } \
\hline \text { Attorney } & 8 & 41 & 87 & 36 & 172 \
\hline \begin{array} { c } 
\text { College } \
\text { Professor }
\end{array} & 10 & 38 & 71 & 31 & 150 \
\hline \text { Secretary } & 21 & 45 & 63 & 49 & 178 \
\hline \text { Store Clerk } & 18 & 44 & 70 & 50 & 182 \
\hline \text { Total } & 57 & 168 & 291 & 166 & 682 \
\hline
\end{array}$$ Suppose one of these people is selected at random.Compute the probability that the person selected was a store clerk.
A)0.084
B)0.099
C)0.316
D)0.267
E)0.026

Quizplus · Accepted Answer

The probability that the person selected was a store clerk is calculated by dividing the total number of store clerks by the total number of people. There are 182 store clerks out of a total of 682 people, so the probability is $182 / 682 = 0.267$.

The Following Contingency Table Provides a Joint Frequency Distribution for a Group