Question

The heights (in cm) of 30 students of class IX are given below:
155, 158, 154, 158, 160, 148, 149, 150, 153, 159, 161, 148, 157, 153, 157, 162, 159, 151, 154, 156, 152, 156, 160, 152, 147, 155, 163, 155, 157, 153

Prepare a frequency distribution table with 160-164 as one of the class intervals.

Answer 1

One of the class intervals is 160–164. This means that class size is 4

Here, the maximum and minimum values of the variate are 163 and 147 respectively.

So the range = 163 – 147 = 16

Here, we will take class size 4. So we must have 5 classes each of size 4

Lower limit of first class interval is;

`a-h/2=147-4/2=145`

And, upper limit of first class interval is:

`a + h/2=147+ 4/2=149`

Therefore, the frequency distribution in which the lower limit is included and upper limit excluded is:

Height (in cm)	Tally marks	Frequency
144-148	|	1
148-152	|||||	5
152-156	||||| |||||	10
156-160	||||| ||||	9
160-164	|||||	5
Total		30