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Frequency polygon
Frequency polygon
Last updated at May 29, 2018 by Teachoo
Example 9 In a city, the weekly observations made in a study of cost of living index are given in the following table Draw a frequency polygon for the data above (without constructing a histogram). Class mark = (π’ππππ ππππ π πππππ‘+πππ€ππ ππππ π πππππ‘)/2 Class mark for 140 β 150 interval = (150 + 140)/2 = 290/2 = 145 We plot class-marks on x axis and number of weeks on y axis Calculating points where frequency = 0 Difference = 155 β 145 = 10 First point = 145 β 10 = 135 Last point = 195 + 10 = 205 So, we plot points (135, 0) & (205, 0)