( VNVI
15. The average height of 12 girls of a class is 158cm, and that of the 18 boys is 165 cm the
average height of the whole class is?
1) 160.2
2) 162.2
3) 152.2
4) 168.2
Answers
158×12+165×18=4866
4866÷30=162.2 so the answer 2
2) 162.2cm
162.2cm is the average height of the total class members.
Step-by-step explanation:
Given:
The average height of 12 girls in a class is 158cm.
The average height of 18 boys is 165 cm.
To find:
The average height of the entire class members.
Solution:
The number of boys and girls in a class and their heights are given.
We need to seek out the average height of the total class members.
The average height of 12 girls in a class is 158cm. This is given by
The average height of girls members in a class =158×12
⇒1896
The average height of 18 boys is 165cm in a class. This is given by
The average height of boys members in a class =18×165
⇒2970
Total class members mean the addition of the number of girls in the class to the number of boys in the class.
Total class members= Number of girls + Number of boys
⇒12+18
⇒30
The Average height of the total class members is given by the addition of the average height of boys and the Average height of women and gets divided by the total class members.
Average height = Average height of girls + Average height of boys
Total class members
⇒1896+2970
30
Average height of the total class members ⇒162.2cm
Hence
The average height of the total class members is 162.2cm.
2) 162.2cm