Frequency Tables
Frequency tables are tables which list the frequency of an event, that is, the number of times an event occurs. There are two types of Frequency tables, Ungrouped and Grouped.
Ungrouped
These are frequency tables which list the frequency (number of times) of observations or data that are ungrouped.
Example:
Below are the scores students in a class of 40 obtained on a quiz graded out of 10.
4 7 9 2 6 8 7 10
5 3 6 8 5 4 2 9
6 6 7 7 6 8 6 8
7 5 4 8 7 7 6 7
8 9 7 6 8 5 10 9
Construct a frequency table for the scores.
| Score | Frequency |
| 2 | 2 |
| 3 | 1 |
| 4 | 3 |
| 5 | 4 |
| 6 | 8 |
| 7 | 9 |
| 8 | 7 |
| 9 | 4 |
| 10 | 2 |
| Total Frequency | 40 |
Note:
(1) The total frequency was obtained by summing the frequencies of all the scores.
(2) The total frequency amount is equal to the amount of students in the class.
Grouped
These are frequency tables which list the frequency (number of times) of observations or data that are grouped. These groups are often called classes.
Example:
Below is a list of the points each basketball team scored in the first half of all 42 games played on the 7th of January 2007, in the NCAA, National Collegiate Athletic Association.
20 20 30 26 47 35 46
22 17 27 30 35 42 47
48 30 21 18 27 36 43
24 19 28 34 37 44 48
49 40 38 33 28 19 25
23 18 28 34 38 43 47
Construct a frequency table for the classes: 15-19, 20-25, 26-29, 30-35, 36-39, 40-45, and 46-49.
| Points | Frequency |
| 15 – 19 | 5 |
| 20 – 25 | 7 |
| 26 – 29 | 6 |
| 30 – 35 | 8 |
| 36 – 39 | 4 |
| 40 – 45 | 5 |
| 46 – 49 | 7 |
| Total Frequency | 42 |
Note: In some cases it may be required to add a Tally column to a frequency table.