Q5 of 141 Page 7

The marks obtained out of 50, by 102 students in a Physics test are given in the frequency table below:

Marks (x):

15

20

22

24

25

30

33

38

45

Frequency (f):

5

8

11

20

23

18

13

3

1

Find the average number of marks.

Let the assumed mean (A) = 25

Average number of marks = A +

= 25 + =

= = 26.08 (approx)

The following table gives the number of branches and number of plants in the garden of a school.

No. of branches (x):	2	3	4	5	6
No. of plants (f):	49	43	57	38	13

The following table gives the number of children of 150 families in a village

No. of children (x):	0	1	2	3	4	5
No. of families (f):	10	21	55	42	15	7

Find the average number of children per family.

The number of students absent in a class were recorded every day for 120 days and the information is given in the following frequency table:

No. of students absent (x):	0	1	2	3	4	5	6	7
No. of days (f):	1	4	10	50	34	15	4	2

Find the mean number of students absent per day.

In the first proof reading of a book containing 300 pages the following distribution of misprints was obtained:

No. of misprints per pages (x):	0	1	2	3	4	5
No. of pages (f):	154	95	36	9	5	1

Find the average number of misprints per page.

The marks obtained out of 50, by 102 students in a Physics test are given in the frequency table below:Marks (x):152022242530333845Frequency (f):58112023181331Find the average number of marks.