EXERCISE 21A

(1) The number of members in 20 families are given below:

4, 6, 5, 5, 4, 6, 3, 3, 5, 5, 3, 5, 4, 4, 6, 7, 3, 5, 5, 7

Prepare a frequency distribution of the data.

Solution: Arrange the data in ascending order, we get the observations as

3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 7, 7

We find that

3 occurs 4 times

4 occurs 4 times

5 occurs 7 times

6 occurs 3 times

7 occurs 2 times

(2) A dice was thrown 30 times and the following outcomes were noted:

2, 1, 2, 4, 6, 1, 2, 3, 6, 5, 4, 4, 3, 1, 1, 3, 1, 1, 5, 6, 6, 2, 2, 3, 4, 2, 5, 5, 6, 4

Prepare a frequency table.

Solution: Arrange the data is ascending order, we get the observations as

1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6

We find that

1 occurs 6 times

2 occurs 6 times

3 occurs 4 times

4 occurs 5 times

5 occurs 4 times

6 occurs 5 times

(3) The following data gives the number of children in 40 families:

1, 2, 6, 5, 1, 5, 1, 3, 2, 6, 2, 3, 4, 2, 0, 4, 4, 3, 2, 2, 0, 0, 1, 2, 2, 4, 3, 2, 1, 0, 5, 1,
2, 4, 3, 4, 1, 6, 2, 2.

Represent in the form of a frequency distribution.

Solution: Arrange the data is ascending order, we get the observations as

0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4,
4, 4, 4, 5, 5, 5, 6, 6, 6

0 occurs 4 times

1 occurs 7 times

2 occurs 12 times

3 occurs 5 times

4 occurs 6 times

5 occurs 3 times

6 occurs 3 times