Question

In the class intervals 20 – 25, 25 – 30, 30 – 35, the number 30 is included in the class:

Options

• 20 – 25

• 25 – 30

• 30 – 35

• none of these

Answer 1

30 – 35

Explanation:

For continuous grouped class intervals, the usual convention is that the lower limit is included and the upper limit excluded.

So, 25 – 30 means 25 ≤ x < 30 and 30 is the lower limit of 30 – 35. 

Hence, belongs to 30 – 35.