Statistics: Cumulative Frequency

Understanding event outcomes by their frequency.

One of the most important patterns studied within statistical research are frequency distributions and their cumulativeness to understand events.

In this example we’ll begin with a dataset illustrating adult student ages with the goal of understanding how often certain-aged students participate in school.

Next, I’ll add to my spreadsheet the following columns: Age Intervals to denote the lower and upper bounds of each age interval I wish to study, Upper Limit to denote the largest value within each interval, Frequency to contain how often ages within each interval occurs, and Cumulative Frequency to determine when compared to all previous intervals, how often each occurs.

2-Cumulative-Frequency

Now I will determine and fill-in Age intervals to study.

3-Cumulative-Frequency

For each interval I’ll update the Upper Limit column.

4-Cumulative-Frequency

Now it is time to leverage Excel formulas to perform statistical analysis.

First, I’ll use the FREQUENCY() function to calculate values for the Cumulative Frequency column by referring the list of ages and each interval’s Upper Limit. Next, I’ll duplicate (drag) that formula to all remaining cells in that column for each interval.

5-Cumulative-Frequency

Now I’ll populate my Frequency column by beginning with the first value in Cumulative Frequency, then subtracting each subsequent frequency from the previous value for all frequencies.

As you can see, students ages 20-30 constitute the most common age of students with the second group being 50-60, no students between 30-40, and a total of 19 students.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s