Question

The mean of 10 observations is 25 .if one observations namely is deleted the new mean is

Answer 1

x1+x2.....+x10/10=25
x1+x2...+x10=250
if 1 observation deleted
x1+x2....+x9/9=x
x1+x2...+x9=9x
9x+x=250
10x=250
x=250/10
x=25
9x=9(25)
225 is answer