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# If class mid-points in a frequency distribution of a group of persons are: 125, 132, 139, 146, 153, 160, 167, 174, 181 pounds, find: (a) size of the class intervals, and (b) the class boundaries.

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Solution

## From the mid-values the class size is calculated using the following formula. Class Size = Mid value of one class - Mid value of the preceding class Class Size = 132 - 125 = 7 Now, the upper and lower limit for each of the class intervals is calculated as follows. $\mathrm{Lower}\mathrm{limit}=\mathrm{Mid}\mathrm{value}-\frac{\mathrm{Class}\mathrm{Size}}{2}\phantom{\rule{0ex}{0ex}}\mathrm{or},\mathrm{Lower}\mathrm{limit}=\mathrm{Mid}\mathrm{value}-\frac{7}{2}\phantom{\rule{0ex}{0ex}}\mathrm{Upper}\mathrm{limit}=\mathrm{Mid}\mathrm{value}+\frac{\mathrm{Class}\mathrm{Size}}{2}\phantom{\rule{0ex}{0ex}}\mathrm{or},\mathrm{Upper}\mathrm{limit}=\mathrm{Mid}\mathrm{value}+\frac{7}{2}$ Mid Value Class Interval 125 132 139 146 153 160 167 174 181 121.5 − 128.5 128.5 − 135.5 135.5 − 142.5 142.5 − 149.5 149.5 − 156.5 156.5 − 163.5 163.5 − 170.5 170.5 − 177.5 177.5 − 184.5  Suggest Corrections  1      Similar questions  Related Videos   Frequency Distribution Table
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