Question

Use the table given below to find:
(a) The actual class limits of the fourth class.
(b) The class boundaries of the sixth class.
(c) The class mark of the third class.
(d) The upper and lower limits of the fifth class.
(e) The size of the third class.

Class Interval	Frequency
30 - 34	7
35 - 39	10
40 - 44	12
45 - 49	13
50 - 54	8
55 - 59	4

Answer 1

(a) The actual class limit of the fourth class will be  44.5 - 49.5.

(b) The class boundaries of the sixth class will be 54.5 - 59.5

(c) The class mark of the third class will be the average of the lower bound and the upper bound of the interval. Therefore the class mark will be: `( 40 + 44)/( 2)` = 42

(d) The upper and lower limit of the fifth class is 54 and 50 respectively.

(e) The size of the third class will be 44 - 40 + 1 = 5.