The proportion concept is used to determine the value of the unknown variable X. Consider that the value of X needs to be determined in the equation given below. dfrac {36} {6} = dfrac {X} {10} 636 = 10X The solution is given as follows dfrac {36} {6} = dfrac {X} {10} 636 = 10X 6 = dfrac {X} {10} 6 = 10X X = 6 times10 X = 6×10 X = 60 X = 60