3 – 7, 8 – 12, 13 – 17, 18 – 22. Which of the following is/are true?
I. The class Interval is 4
II. The class boundaries are 2.5, 7.5, 12.5, 18.5, 22.5
III. The mid-marks are 5, 10, 15, and 20
-
I only
- II only
- III only
- I and II only
- II and III only