Question

The mean of 72 items found 63. If two items misread as27&9 instead 72&90 respectively. Find correct mean

Answer 1

mean of 72 items=63
n
sum of 72 items =63×72
=4536
mis readed as 27&9 instead of 72&90
then new mean =4536-27-9+72+90/63
=74