Gap in Inclusive Class Intervals

A frequency distribution of incomes of 550 employees was made using inclusive class intervals 800–899, 900–999, etc. What is the gap between consecutive class intervals?

Correct Answer Explanation

The gap between upper limit of first class (899) and lower limit of second class (900) = 900 − 899 = 1.

Adjustment Process:

• Gap = 900 − 899 = 1
• Adjustment value = 1/2 = 0.5
• New class: 800–899 → 799.5–899.5
• New class: 900–999 → 899.5–999.5
• This ensures continuity of the data in the frequency distribution.