Question

The average of 100 observations is 50. What will be the new average if in one of the observations, 50 is replaced by 100?

Answer 1

Average of 100 observations = 50

$\Rightarrow \frac{\text{Total}}{100}=50\Rightarrow \text{Total}=5000$

50 is replaced by 100, hence the difference between the values $=100-50=50$

$\therefore \text{New total}=5000+50=5050$

New average $=\frac{5050}{100}=50.50$