Question

m is the mean of 10 observations. if one observation ‘n' is removed, then the new mean is...........

A.) 10m - n/9

B.) n - 10m/9

C.) 10m + n/9

D.) n + 10m/9

Answer 1

answer is A as the previous mean is m=10m÷10 when we remove n then the mean becomes m=10m-n÷9