Question

The mean of $100$ items was $60$ . Later it was found that two items were misread as $69$ and $96$ instead of $66$ and $99$ respectively. The correct mean of the $100$ items is

• A. $60$
• B. $61$
• C. $60.5$
• D. $61.5$

Answer 1

Answer: (A)

$60$

Answer 2

Incorrect mean $= 60$,
Incorrect sum $= 6000$
$\therefore$ Correct sum $= 6000 -69 - 96 + 66 + 99$
$= 6000$
$\therefore$ Correct mean $= \frac{6000}{100} =60$