Question

The sum of (x+4) observations is x^2+x -12 then mean is

Answer 1

Step-by-step explanation:

sum = x²+x-12 = x²+4x-3x-12 = x(x+4)-3(x+4)

= (x-3)(x+4)

mean = sum/ no. of observations

= x²+x-12/ (x+4)

= (x+4)(x-3)/ (x+4) = x-3