Question

A company manufactures car batteries of a particular type. The lives (in years) of 40 such batteries were recorded as follows:-

2.6	3.0	3.7	3.2	2.2	4.1	3.5	4.5
3.5	2.3	3.2	3.4	3.8	3.2	4.6	3.7
2.5	4.4	3.4	3.3	2.9	3.0	4.3	2.8
3.5	3.2	3.9	3.2	3.2	3.1	3.7	3.4
4.6	3.8	3.2	2.6	3.5	4.2	2.9	3.6

Construct a grouped frequency distribution table for this data, using class intervals of size 0.5 starting from the intervals 2 − 2.5.

Answer 1

A grouped frequency table of class size 0.5 has to be constructed, starting from class interval 2 − 2.5.

Therefore, the class intervals will be 2 − 2.5, 2.5 − 3, 3 − 3.5…

By observing the data given above, the required grouped frequency distribution table can be constructed as follows.

Lives of batteries (in years)	Number of batteries
2 − 2.5	2
2.5 − 3.0	6
3.0 − 3.5	14
3.5− 4.0	11
4.0 − 4.5	4
4.5 − 5.0	3
Total	40