Chapter 12.1, Problem 60S

To determine

To find : Average score of whole class.

Answer to Problem 60S

  $80$

Explanation of Solution

Given information :

Average score of $20$ students = $83$

And Average score of $10$ students = $74$

Class strength = $30$ students

Formula Used:

Average = $\frac{\text{Sum of observations}}{\text{Number of observations}}$

Calculation :

Score of $\text{20}$ students $=83\times 20=1660$

Score of $10$ students $=74\times 10=740$

Total score by $30$ students $=1660+740=2400$

Average score of class $=\frac{2400}{30}=80$