Page 152 - Revised Maths Wisdom Class - 6

150 MATHS

● A tabular arrangement of the ungrouped data showing the frequency of each item is called frequency
distribution and the table is called the frequency distribution table.

Making Frequency Distribution Table
To make frequency distribution table, we follow these steps:

Step 1: Collect the raw data and array it.
Step 2: Make three columns—first for observation, second for tally marks and third for total of tally marks
showing the frequency of each observation.
Step 3: For each observation in the raw data, put a bar in the second column. Record these tally marks in groups
of five with the fifth bar crossing the other four diagonally ( ).
Step 4: Count the tally marks for each observation and write in the third column.

Let us learn through examples.

ILLUSTRATIONS

Example 1: Prepare a frequency table of the following ages (in years) of 35 students of class VI in a school.

13, 14, 13, 12, 15, 13, 14, 13, 14, 16, 12, 14, 13, 12, 17, 13, 12, 13, 13, 14, 15, 12, 17, 13, 14, 13,
14, 13, 16, 12, 14, 15, 12, 16, 14

Solution: Arranging the data in descending order.
17, 17, 16, 16, 16, 15, 15, 15, 14, 14, 14, 14, 14, 14, 14, 14, 14, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 12, 12, 12, 12, 12, 12, 12
Age Tally Marks Frequency

12 || 7
13 | 11

14 |||| 9
15 ||| 3

16 ||| 3
17 || 2
Total = 35

Example 2: A die was rolled 30 times with the following results. Prepare the frequency table.
6, 5, 4, 4, 5, 6, 1, 2, 1, 6, 4, 3, 3, 3, 4, 2, 2, 5, 6, 4, 1, 2, 4, 3, 5, 5, 3, 3, 4, 2
Solution:
Number Tally Marks Frequency
1 ||| 3
2 5

3 | 6
4 || 7
5 5

6 |||| 4
Total = 30