Let the cost of the goods be C. The profit or loss (negative profit) is given by S-C where S is the sale revenue.
S=$94.50. 100(S-C)/C is the percentage profit or loss=100(94.50-C)/C=-12, or 94.50/C-1=-0.12, because it's a loss of 12%. 94.50/C=0.88 so C=94.5/0.88=$107.39. Profit=94.5-107.39=-$12.89.