Cumulative Frequency Distributions. In Exercises 21 and 22, construct the cumulative frequency distribution that corresponds to the frequency distribution in the exercise indicated.

Exercise 6 (Age of Best Actor When Oscar Was Won)

The grouped frequency distribution of the ages (in years) of the best actors when the Oscar was won is given.

Thecumulative frequency distribution is obtained by adding the frequencies of successive classes. It represents the sum of all frequencies of a class interval equal to and less than it.

The table below shows the frequencies of ages (in years) of the best actor when Oscar was won:

To construct the cumulative frequency distribution, the first class interval should be changed to less than the lower limit of the second class interval; the second class interval should be changed to less than the lower limit of the third class interval, and so on.

Also, the cumulative frequency for each class is obtained by adding the frequencies of successive classes.

The cumulative frequencies are obtained as shown below: