Question

The mean marks scored by $40$ students were found to be $60$. Later it was observed that a score of $48$ was misread as $84$. Then the correct mean is __________.

• A. $58$
• B. $58.2$
• C. $59.1$
• D. $59$

Answer 1

The correct option is C $59.1$

We have $60=\frac{\text{sum}}{40}$

thus $\text{sum}=60\times 40=2400$

$48$ was misread as $84$

So, $\text{corrected sum}=\text{sum}-84+48$

$\text{correct sum}=2400-36=2364$

$\text{correct mean}=\frac{2364}{40}=59.1$