Question

The mean of 100 observations was found to be 50. If two
observations were wrongly taken as 42 & 13 instead of 24 & 26,
find the correct mean.

Answer 1

Answer:

The total no. of observations are 100

The mean of those observations are 30

So The sum of observations is 30×100=3000

The wrong observations are 32 and 12

Those are to be subtracted from sum of observations

So, 3000−32−12=2956

The correct observations are 23 and 11

Those are to be added

So, 2956+23+11=2990

The mean is given by

100

2990

=29.9