Instruction 2.4
The following are the durations in minutes of a sample of long-distance phone calls made within Australia reported by one long-distance carrier.
$$\begin{array} { | l | l | }
\hline \text { Time (in Minutes) } & \text { Relative Frequency } \
\hline0 \text { but less than 5 } & 0.37 \
\hline 5 \text { but less than 10 } & 0.22 \
\hline \begin{array} { l }
10 \text { but less than } \
15
\end{array} & 0.15 \
\hline \begin{array} { l }
15 \text { but less than } \
20
\end{array} & 0.10 \
\hline \begin{array} { l }
20 \text { but less than } \
25
\end{array} & 0.07 \
\hline \begin{array} { l }
25 \text { but less than } \
30
\end{array} & 0.07 \
\hline 30 \text { or more } & 0.02 \
\hline
\end{array}$$
-Referring to Instruction 2.4,if 1,000 calls were randomly sampled,how many calls lasted under 10 minutes?
A) 590
B) 370
C) 410
D) 220

Question

Instruction 2.4
The following are the durations in minutes of a sample of long-distance phone calls made within Australia reported by one long-distance carrier.
 $$\begin{array} { | l | l | } 
\hline \text { Time (in Minutes) } & \text { Relative Frequency } \
\hline0 \text { but less than 5 } & 0.37 \
\hline 5 \text { but less than 10 } & 0.22 \
\hline \begin{array} { l } 
10 \text { but less than } \
15
\end{array} & 0.15 \
\hline \begin{array} { l } 
15 \text { but less than } \
20
\end{array} & 0.10 \
\hline \begin{array} { l } 
20 \text { but less than } \
25
\end{array} & 0.07 \
\hline \begin{array} { l } 
25 \text { but less than } \
30
\end{array} & 0.07 \
\hline 30 \text { or more } & 0.02 \
\hline
\end{array}$$
-Referring to Instruction 2.4,if 1,000 calls were randomly sampled,how many calls lasted under 10 minutes?
A) 590
B) 370
C) 410
D) 220

Quizplus · Accepted Answer

The calls that lasted under 10 minutes include those in the 0-5 minute range and the 5-10 minute range. The relative frequencies for these ranges are 0.37 and 0.22, respectively. Adding these gives 0.37 + 0.22 = 0.59. Since the sample size is 1,000 calls, 0.59 of 1,000 calls is 590 calls.

Instruction 2 -Referring to Instruction 2