Cumulative Frequency Curve Or Ogive Graph

Cumulative Frequency Curve Or Ogive Graph

In a cumulative frequency polygon or curves, the cumulative frequencies are plotted against the lower and upper limits of class intervals depending upon the manner in which the series has been cumulated. There are two methods of constructing a frequency polygon or an Ogive.

(i) Less than method (ii) More than method

In ungrouped frequency distribution:

question 1. The marks obtained by 400 students in medical entrance exam are given in the following table.

(i) Draw Ogive by less than method.

(ii) Draw Ogive by more than method.

(iii) Find the number of examinees, who have obtained the marks less than 625.

(iv) Find the number of examinees, who have obtained 625 and more than marks.

Solution: (i) Cumulative frequency table for less than Ogive method is as following.

Following are the Ogive for the above cumulative frequency table by applying the given method and the assumed scale.

(ii) Cumulative frequency table for more than Ogive method is as following : -

Following are the Ogive for the above cumulative frequency table.

(iii) So, the number of examinees, scoring marks less than 625 are approximately 220.

(iv) So, the number of examinees, scoring marks 625 and more will be approximately 190.