The answer is 15.18 grams. In the problem, the weight and the conversion factor is already given. Based on all the numbers given, we now know that for every pound, Jane must consume 0.11 grams of the supplement. With this, all you need to do is multiply the weight (in pounds) and the amount of supplement per pound. The solution is 138 lbs. x 0.11 grams per 1 lb. = 15.18 grams. This means that Jane should take 15.18 grams of the supplement.