Question

The average of 4 values is 20 and when a quantity is added to each value the average is 22. find the quantity

Answer 1

(A1+A2+A3+A4)÷4=20
A1+A2+A3+A4=80

(A1+x+A2+x+A3+x+A4+x)÷8=22

A1+A2+A3+A4+4x=176(22×8)
80+4x=176
4x = 96

x =24(96÷4)

Answer 2

Answer:

a,b,c,d/4=20.

quantity added

a+q+b+q+c+q+d+q/4=22

a+b+c+d+4d/4=22

a+b+c+d/4+q=22

20+q=22

q=22-20

q=2