A cumulative frequency table shows the number of values that lie in or below a given interval. Start by identifying the minimum and maximum data values and defining the intervals.
Example Table:
Feet
Frequency
Cumulative Frequency
100 - 149
2
2
150 - 199
3
5
200 - 249
3
8
250 - 299
2
10
300 - 349
2
12
Practice makes perfect
A cumulativefrequency table shows the number of values that lie in or below an interval. To make a cumulative frequency table, we will start by identifying the minimum and maximum data values.
Then we can define the intervals for each line of our table.
105, 245, 300, 234, 225, 156,
180, 308, 250, 114, 150, 285
The minimum value is 105 and the maximum value is 308.
In this case, intervals of 50 seem reasonable. Let's list them in the first column of our cumulative frequency table.
Feet
Frequency
Cumulative Frequency
100 - 149
150 - 199
200 - 249
250 - 299
300 - 349
Now, let's count the number of values in each interval.
105, 245, 300, 234, 225, 156,
180, 308, 250, 114, 150, 285
Looking at the data, we can see that there are 2 values in the first interval, 3 values in the second interval, 3 values in the third interval, 2 values in the fourth interval, and 2 values in the fifth interval. Now we can complete the second column of our table.
Feet
Frequency
Cumulative Frequency
100 - 149
2
150 - 199
3
200 - 249
3
250 - 299
2
300 - 349
2
Finally, for the last column we add the frequency of each interval to the frequencies of all the previous intervals. We will do this by adding the frequency of each interval to the cumulative frequency of the previous interval.
