Frequency Table Example

A group of 12 students were asked, "How many siblings do you have?" A bird flies overhead and drops siblings randomly so that they are in no particular order. The sentence appears, "The siblings are not ordered."

One way to organize the data is to group it. A frequency chart appears. It has the columns Data and Frequency. The Data is the number of siblings. Under Data we have 1, 2, 3, 4, 5 siblings. The Frequency column contains the number of students who have the number of siblings displayed under the Data column. Under Frequency we have 3, 2, 2, 4, 1 which adds up to 12. There are 3 students with 1 sibling, 2 students with 2 siblings, 2 students with 3 siblings, 4 students with 4 siblings, and 1 student with 5 siblings.

The following question appears. "What fraction of those students have 5 siblings?"

The chart appears with two new columns: Relative Frequency and Cumulative Relative Frequency. The Relative Frequency column displays 3/12, 2/12, 2/12, 4/12, and 1/12. This means that 3/12 of the students in the survey have 1 sibling, 2/12 have 2 siblings, 2/12 have 3 siblings, 4/12 have 4 siblings, and 1/12 have 5 siblings. The answer to the question is 1/12 have 5 siblings.

The next questions is asked. The question is, "What fraction of those students have at most 3 siblings?"

The chart appears with all 4 columns: Data, Frequency, Relative Frequency, and Cumulative Relative Frequency. From the chart, "at most 3" means 1, 2, or 3 siblings. In the Data column, 1, 2, and 3 are checked. In the Frequency column, 3, 2, and 2 (frequencies for Data 1, 2, and 3) are circled. The corresponding entries in the Relative Frequency column are 3/12, 2/12, and 2/12. Adding these together we get 7/12. The third entry of the Cumulative Relative Frequency column is 7/12 and it is circled. The answer is that 7/12 of the students have at most 3 siblings.