The arithmetic average of 10 numbers -2, -5,-2, 5, x , -3 10, 3, 8, -10 is 8 find x

AS

Arithmetic average = Sum of all the numbers /Total numbers

SO arithmetic average= {(-2)+(-5)+(-2)+(5)+(x)+(-3)+(10)+(3)+(8)+(-10)} / 10

                                      ={4x} /10

                                      =0.4 x

As Given Arithmetic average= 8

so   0.4x =8

       Dividing 0.4 Both sides

     0.4x/0.4 = 8/0.4

      x= 20

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