Question

The arithmetic mean of $10$ numbers was computed as $7.6$. It was later discovered that a number $8$ was wrongly read as $3$ during the computation. What should be the correct mean?

• A. $7.1$
• B. $7.6$
• C. $8.1$
• D. $8.6$

Answer 1

The correct option is C $8.1$

Arithmetic mean of $10$ numbers is $7.6$.

Therefore, sum of numbers $=10\times 7.6=76$

$8$ was wrongly read as $3$ during computation.

Therefore, correct sum of numbers $=76+8-3=81$

Correct mean $=81÷10=8.1$