$$\begin{array}{l}
\text { Approximate the sample variance given the following frequency distribution. }\
\begin{array} { c c }
\hline \text { Class } & \text { Frequency } \
\hline 0 - 19 & 14 \
20 - 39 & 15 \
40 - 59 & 9 \
60 - 79 & 9 \
80 - 99 & 9 \
\hline
\end{array}
\end{array}$$
A) 28.5
B) 795.9
C) 810.4
D) 28.2

Question

$$\begin{array}{l}
\text { Approximate the sample variance given the following frequency distribution. }\
\begin{array} { c c } 
\hline \text { Class } & \text { Frequency } \
\hline 0 - 19 & 14 \
20 - 39 & 15 \
40 - 59 & 9 \
60 - 79 & 9 \
80 - 99 & 9 \
\hline
\end{array}
\end{array}$$
A) 28.5
B) 795.9
C) 810.4
D) 28.2

Quizplus · Accepted Answer

To approximate the sample variance, calculate the midpoint for each class, multiply by the frequency, find the mean, then use the formula for variance. The correct calculation leads to 810.4.

A) 285 B) 795

A) 285
B) 795