Question

The mean of 200 items was found was 50 . Later on it was discovered that the two items were misread as 92 and 8 instead of 192 and 88 . Find correct mean

Answer 1

We know that,
Mean = (Total sum of Observation) ÷ (Total number of Observation)


$200 = \frac{x}{50}$
$x = 200 \times 50$
$x = 10000$
Now subtracting misread Observations

10000-92-8 = 9900

Correction in error

9900+192+88 = 10180

$mean = \frac{10180}{50}$
mean = 203.6