# RS Aggarwal Solutions for Class 10 Maths Chapter 18 Mean, Median, Mode of Grouped Data, Cumulative Frequency Graph and Ogive

Cumulative histograms, also known as Ogives, are graphs that can be used to determine how many data values lie above or below a particular value in a data set. The cumulative frequency is calculated from a frequency table, by adding each frequency to the total of the frequencies of all data values before it in the data set. The last value for the cumulative frequency will always be equal to the total number of data values since all frequencies will already have been added to the previous total.

An Ogive is drawn by

• Plotting the beginning of the first interval at a y-value of zero;
• Plotting the end of every interval at the y-value equal to the cumulative count for that interval; and
• Connecting the points on the plot with straight lines.

Chapter 18 of RS Aggarwal Class 10 Maths deals with three measures of central tendency, which is useful for analyzing the data, namely (a) mean (b) median and (c) mode and its comparative study.