Find the indicated probability.
-The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency table below summarizes the results. $$\begin{array} { r | c }
\begin{array} { r }
\text { Waiting Time } \
\text { (minutes) }
\end{array} & \begin{array} { c }
\text { Number of } \
\text { Customers }
\end{array} \
\hline 0 - 3 & 10 \
4 - 7 & 13 \
8 - 11 & 14 \
12 - 15 & 4 \
16 - 19 & 6 \
20 - 23 & 2 \
24 - 27 & 2
\end{array}$$ If one of these customers is selected at random, what is the probability that their waiting time is at
Least 12 minutes or between 8 and 15 minutes?
A)0.692
B)0.078
C)0.549
D)0.627

Question

Find the indicated probability.
-The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency table below summarizes the results. $$\begin{array} { r | c } 
\begin{array} { r } 
\text { Waiting Time } \
\text { (minutes) }
\end{array} & \begin{array} { c } 
\text { Number of } \
\text { Customers }
\end{array} \
\hline 0 - 3 & 10 \
4 - 7 & 13 \
8 - 11 & 14 \
12 - 15 & 4 \
16 - 19 & 6 \
20 - 23 & 2 \
24 - 27 & 2
\end{array}$$ If one of these customers is selected at random, what is the probability that their waiting time is at
Least 12 minutes or between 8 and 15 minutes?
A)0.692
B)0.078
C)0.549
D)0.627

Quizplus · Accepted Answer

First, calculate the total number of customers: $10 + 13 + 14 + 4 + 6 + 2 + 2 = 51$. The probability of selecting a customer who waited at least 12 minutes includes those who waited 12-15, 16-19, 20-23, and 24-27 minutes: $4 + 6 + 2 + 2 = 14$ customers. The probability of selecting a customer who waited between 8 and 15 minutes includes those who waited 8-11 and 12-15 minutes: $14 + 4 = 18$ customers. However, since those who waited 12-15 minutes are included in both categories, we don't double count them. Thus, the total unique count is still 14 customers. Therefore, the probability is $14 / 51$, which simplifies to approximately 0.549.

Find the Indicated Probability If One of These Customers Is Selected at Random, What