Page 3 - lesson notes 62 xi MOD variance & Lorenz curve
P. 3
Lorenz Curve
It is a curve that shows deviation of actual distribution from the showing equal
distribution.
(i) Construction of the Lorenz Curve
• Calculate class mid-points
• Calculate cumulative frequencies as in column 6
• Express the grand total of column 3 and 6 as 100 and convert the cumulative
totals in these columns in to percentage.
• Now, on the graph paper, take the cumulative percentage of the variable on Y-axis
and cumulative percentages of X-axis.
• Draw a line joining co-ordinate (0, 0) with (100,100) this is called the line of equal
distribution.
