## 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