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

Explanation

Mean of 200 items = 50

Since Mean = Sum of 200 items / No of items

Sum of 200 items = `( 50 xx 200) = 10,000`
Correct sum of 200 items
= ( 10,000 -( sum of wrong items ) +( sum of correct items) )
= { 10,000 -(92 +8) +(192 +88)}
= ( 10,000 - 100 +280) = 10180.
Correct mean =` ((10180)/200) = 50.9`