Question

if the sum of the deviations of a set of value X1 X2 X3 in excel measure from 58 - 10 and the sum of deviation of the values from 46 is 70 then find its mean

Answer 1

The deviations of x1, x2,... xn from 50 are x1 - 50 , x2 - 50 ,... xn -50 
Hence the sum is 
(x1 - 50 ) + (x2 - 50 ) + ...... (xn - 50) = -10 
(x1 + x2 + ....xn) - 50 n = -10 ...(1) 

similarly we have 

(x1 + x2 + .....xn) - 46n = 70 ...(2) 

equation (2) - (1) gives 

-4n = -80 

n = 20 

substituting the value of n in (1) 

(x1 + x2 + ....xn) - 50 (20) = -10 
(x1 + x2 + ....xn) = 990 

Hence the mean 
(x1 + x2 + ....xn) /n = 990/20 = 49.5

Hope This helps :)

Answer 2

here is your correct answer