Let x be the original value. An increase in 12% means an additional 0.12x. Thus, an 12% in x means x + 0.12x = 1.12x.

Then solve the equation 1.12x = 130. Rounding to the nearest hunderdth decimal point yields x = 116.07.

What you did was 0.12 * 130 = 15.6 which means 12% of the new value. You want to find 12% of the original value and then subtract that from 130. The words in mathematical form yields x = 130 - 0.12x which yields x = 116.07.

Second problem - According to the directions, I'm assuming they want a ratio of two integers like 1 : 2 or 3 : 5 and not a ratio of two fractions.

1 1/2 = 1 + 1/2 = 1 + 0.5 = 1.5 = 1.5/1 = 1.5/1 * 10/10 = 15/10 = 3/2

3 1/4 = 3 + 1/4 = 3 + 0.25 = 3.25 = 3.25/1 = 3.25 * 100/100 = 325/100 = 13/4

1 1/2 : 3 1/4 = (3/2) : (13/4) = (3/2) / (13/4) = (3/2) * (4/13) = 12/26 = 6/13 = 6 : 13