If the mean of m observations out of n observations is n and the mean of remaining observations is m, then what is the mean of all n observations?
Correct Answer: 2m \u2013m^2\/n
Mean of m observations is n
Mean of n-m observations is m
So total = nm+ (n-m)m
Total observations = n
Mean = Total / Total observations = (2mn-m^2)/n = 2m –m^2/n