Roger N. answered 03/27/19
. BE in Civil Engineering . Senior Structural/Civil Engineer
This is a ratio problem 4/3 = blank /12 , let blank the unknown value = X, then
4/3 = X /12, cross multiply, 3 x X = 4 x 12 , 3 x X = 48, divide both sides by 3, ( 3X/3) = (48/3), and X = 16
The solution is 16 which is the blank value