The mean of 200 items was 50. Later on it was discovered that 2 items were misread as 92 and 8 instead of 192 and 88. Find the correct mean.
Since,
Mean of 200 items = 50
Sum of 200 items/ Number of items = Mean
Sum of 200 items = Mean x number of items
= 50 x 200
= 10,000
Wrong sum of 200 items = 10,000
Correct sum = 10,000 + 192 +88 - 92 - 8 [As we add the correct items and subtract the wrong items]
= 10,280 - 100
= 10,180
Therefore,
Correct mean = 10,180/ 200
= 50.9