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 byplotting the beginning of the first interval at a yy-value of zero;plotting the end of every interval at the yy-value equal to the cumulative count for that interval; andconnecting the points on the plot with straight lines.
In this way, the end of the final interval will always be at the total number of data since we will have added up across all intervals.To make a histogram, follow these steps:On the vertical axis, place frequencies. Label this axis "Frequency".On the horizontal axis, place the lower value of each interval. ...Draw a bar extending from the lower value of each interval to the lower value of the next interval.