Inclusive Class Interval Second Class

In the inclusive form of class intervals for marks (0–100), the second class interval is:

Correct Answer Explanation

In the inclusive form, the second class interval is 11–20 (not 10–20).

Inclusive vs Exclusive for marks (0–100):

• Inclusive form: 0–10, 11–20, 21–30, 31–40, ..., 91–100
• Exclusive form: 0–10, 10–20, 20–30, 30–40, ..., 90–100

Key Difference:

• In inclusive: both limits belong to same class → gap between classes (10 and 11).
• In exclusive: upper limit of one class = lower limit of next class → continuity maintained.
• Marks are a discrete variable (whole numbers only) → both forms can be used.