Given below is a

(a) Second class interval is 20 – 30

⇒ Its lower limit = 20

(b) Last class interval is 50 – 60

⇒ Its upper limit = 60

(c) The third class is 30 – 40. Its frequency is 4.

(d) The interval that has a frequency of 10 is 20 – 30.

(e) The lowest frequency is 4 which corresponds to the interval 30 – 40.

(f) Class size = Upper Limit – Lower Limit

⇒ Class size is 10.