NCERT Class 9 Mathematics

244 MATHEMATICS

Now it is possible for us to include the weights of the new students in these classes.
But, another problem crops up because 35.5 appears in both the classes 30.5 - 35.5
and 35.5 - 40.5. In which class do you think this weight should be considered?

If it is considered in both classes, it will be counted twice.

By convention, we consider 35.5 in the class 35.5 - 40.5 and not in 30.5 - 35.5.
Similarly, 40.5 is considered in 40.5 - 45.5 and not in 35.5 - 40.5.

So, the new weights 35.5 kg and 40.5 kg would be included in 35.5 - 40.5 and
40.5 - 45.5, respectively. Now, with these assumptions, the new frequency distribution
table will be as shown below:

Table 14.4

Weights (in kg) Number of students

30.5-35.5 9

35.5-40.5 6

40.5-45.5 15

45.5-50.5 3

50.5-55.5 1

55.5-60.5 2

60.5-65.5 2

65.5-70.5 1

70.5-75.5 1

Total 40

Now, let us move to the data collected by you in Activity 1. This time we ask you to
present these as frequency distribution tables.

Activity 2 : Continuing with the same four groups, change your data to frequency
distribution tables.Choose convenient classes with suitable class-sizes, keeping in mind
the range of the data and the type of data.