What is meant by cumulative frequency?
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What is meant by cumulative frequency?
The cumulative frequency of an item is the total frequency of all items that are less than or equal to the given item.
Cumulative frequency is a running total of the frequencies.
How do you draw a cumulative frequency diagram?
To draw a cumulative frequency diagram:
For each group, plot the cumulative frequency at the endpoint of the group
Join the points together with a smooth curve that is always increasing
True or False?
To draw a cumulative frequency diagram, you plot the midpoint of a group against its frequency.
False.
To draw a cumulative frequency diagram, you do not plot the midpoint of a group against its frequency.
You plot the endpoint of a group against its cumulative frequency.
If the total frequency is 100, how do you use a cumulative frequency diagram to estimate the median value?
If the total frequency is 100, you can use a cumulative frequency diagram to estimate the median value.
Draw a horizontal line from 50 on the vertical axis to the curve
Draw a vertical line down from this point on the curve to the horizontal axis
The value on the horizontal axis is an estimate of the median
How can you estimate the lower quartile using a cumulative frequency diagram?
To estimate the lower quartile using a cumulative frequency diagram:
Divide the total frequency by 4
Draw a horizontal line from the result on the vertical axis to the curve
Draw a vertical line down from this point to the axis
The number on the horizontal axis is an estimate for the lower quartile