Presentation of Data — Economics STD 11 Commerce — Question

A frequency distribution gives the number of observations that lie in any class interval whereas the cumulative frequency distribution gives the number of frequencies that lie below any mark or above any given mark. When derived from a frequency distribution, the cumulative frequency distribution of one kind gives the number of observations less than the lower boundaries of the successive class and the cumulative frequency distribution of the second kind gives the number of observations that exceed the lower boundaries of the class which are respectively known as the less than and greater than the cumulative frequency distribution. If we draw frequency polygon to the above two distribution we get cumulative frequency polygon (less than & greater than). If we draw a frequency curve to the above two distribution in the same graph, we get cumulative frequency curve or Ogive.Steps Involved:

1. Find the cumulative frequencies of the given frequencies by "less than method' or 'more than method' as you need.
2. Less than type cumulative frequencies will give less than type ogive and more type cumulative frequencies will give less than type ogive.
3. Variable under study is taken on X-axis.
4. Cumulative Frequencies are taken on Y-axis.
5. Both the axis should be clearly labeled and scale of measurement should be clearly shown.
6. Various points are plotted on graph.
7. By joining these points we get ogive or cumulative frequency curve.