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So, we make a frequency distribution table for the given data to get the meaningful conclusions.

The number of times an observation is repeated is known as the frequency of that observation.
In the collected data,

17 24 23 17 11 17 23 21 20 21
24 11 17 15 19 20 11 17 17 13

11 is repeated 3 times, so 3 is the frequency of 11; 17 is repeated 6 times, so 6 is the frequency of
17, and so on.

Frequency of any observation is represented by ‘f ’.

To form the frequency distribution table, we follow the following steps:
Step 1: Arrange the given observations in ascending or descending order.

Step 2: Create a table and write each observation in first column.

Step 3: Put tally marks in the second column against the respective observations.

Step 4: Write the frequencies in the third column of their respective observations.
Example 1: The heights (in cm) of 30 soldiers in an army camp are given below. Express the data
in form of a frequency distribution table.

153 162 155 153 155 176 153 155 162 184

176 155 162 162 184 171 153 162 155 176

155 155 162 155 153 171 155 162 155 155

Solution: Arrange the given observations in ascending order:

153 153 153 153 153 155 155 155 155 155
155 155 155 155 155 155 162 162 162 162

162 162 162 171 171 176 176 176 184 184

Now, construct frequency distribution table.

Heights of the soldiers (in cm) Tally Marks Number of soldiers (Frequency)

153 5

155 11

162 7

171 2

176 3

184 2

Total 30

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