Question

The number of books in different shelves of a library are as follows:
30, 32, 28, 24, 20, 25, 38, 37, 40, 45, 16, 20
19, 24, 27, 30, 32, 34, 35, 42, 27, 28, 19, 34,
38, 39, 42, 29, 24, 27, 22, 29, 31, 19, 27, 25
28, 23, 24, 32, 34, 18, 27, 25, 37, 31, 24, 23,
43, 32, 28, 31, 24, 23, 26, 36, 32, 29, 28, 21.
Prepare a cumulative frequency distribution table using 45-49 as the last class interval.

Answer 1

Minimum number of book shelves is 16 and maximum number of book shelves is 45
Range = maximum B. S – Minimum B. S
= 45 – 16
= 29
Given class interval = 45 – 49. So class size
= 49-45 = 4.

∴ Number of classes = `"Range"/"Class size"=29/4=7.25`

⇒ Number of classes = 8.

The cumulative frequencies distribution is as

No. of Books	No. of shelves (Frequency)	Cumulative frequency
13-17	1	1
17-21	6	7
21-25	11	18
25-29	15	33
29-33	12	45
33-37	5	50
37-41	6	56
41-45	3	59
45-49	1	60