## ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 15 Data Handling Ex 15.4

Question 1.

Find the mean of the following data :

(i) 40, 30, 30, 0, 26, 60

(ii) 3, 5, 7, 9, 11, 13, 15

Solution:

(i) Mean of 40, 30, 30, 0, 26, 60

No. of data (n) = 6

∴ Mean = \(\frac{40+30+30+0+26+60}{6}=\frac{186}{6}=31\)

(ii) Mean of 3, 5, 7, 9, 11, 13, 15

No. of data = 7

∴ Mean = \(\frac{3+5+7+9+11+13+15}{7}=\frac{63}{7}=9\)

Question 2.

Find the mean of the first five even whole numbers.

Solution:

First five even whole numbers are 0, 2, 4, 6, 8

Number of data = 5

∴ Mean = \(\frac{0+2+4+6+8}{5}=\frac{20}{5}=4\)

Question 3.

A batsman scored the following number of runs in six innings :

36, 35, 50, 46, 60, 55

Calculate the mean runs scored by him in an inning.

Solution:

In six innings, run scored was

36, 35, 50, 46, 60, 55

∴ Mean = \(\frac{36+35+50+46+60+55}{6}=\frac{282}{6}=47\)

Question 4.

The enrolment in a school for six consecutive years was as follows :

1555, 1670, 1750, 2013, 2540, 2825

Find the mean enrolment of the school for this period.

Solution:

Enrolment for 6 consecutive years is

1555, 1670, 1750, 2013, 2540, 2825

∴ Mean = \(\frac{1555+1670+1750+2013+2540+2825}{6}\)

= \(\frac{12353}{6}\) = 2058.83 = 2059

Question 5.

The marks (out of 100) obtained by a group of students in a science test are :

85, 76, 90, 85, 39, 48, 56, 95, 81, 75

Find the:

(i) highest and lowest marks obtained by the students.

(ii) mean marks obtained by the students.

Solution:

Marks obtained by a group of students in science test

85, 76, 90, 85, 39, 48, 56, 95, 81, 75

(i) Highest marks obtained = 95

Lowest marks = 39

(ii) Mean marks = \(\frac{85+76+90+85+39+48+56+95+81+75}{10}\) (Here n = 10)

= \(\frac{730}{10}\) = 73