Solve the Problem Where N Is the Sum of All Class Frequencies and Distribution

question 145

Multiple Choice

Solve the problem.
-When data are summarized in a frequency distribution, the median can be found by first identifying the median class (the class that contains the median) . We then assume that the values in that class are evenly distributed and we can interpolate. This process can be described by $$\text { median } = ( \text { lower limit of median class } ) + ( \text { class width } ) \left( \frac { \frac { \mathrm { n } + 1 } { 2 } - ( \mathrm { m } + 1 ) } { \text { frequency of median class } } \right)$$ where n is the sum of all class frequencies and m is the sum of the class frequencies that precede the median class. Use this procedure to find the median of the frequency distribution below: $$\begin{array} { l | c } \text { Score } & \text { Frequency } \\\hline 50 - 59 & 21 \\60 - 69 & 24 \\70 - 79 & 22 \\80 - 89 & 16 \\90 - 99 & 17\end{array}$$

• A)74.5
• B)71.8
• C)72.5
• D)72.0