Question

The mean of 96,98,x,102,104,is 100, find x .

Answer 1

Number of observation = n  =  5 [ odd ]
96, 98 , x , 102 , 104
Mean of odd numbers = n + 1 / 2
                                    = 5 + 1 / 2 
                                    = 6 / 2
                                    = 3 rd observation = x
∴ the value of x is 100
u can check it 
Mean = Sum of observations / No: of observations
          = [96 + 98 + 100 + 102 + 104 ] / 5
          = 500 /5
          = 100