must be a very old problem ... gold is going for much more than $125 per ounce these days.
As you might know, there are now businesses asking you to send in your old jewelry in exchange for cash. Imagine you have a solid gold sphere of 15.7 mm diameter which you decide to send in for cash. If the company offers $125 per ounce of gold, how much money will they send you given that the density of gold is 19.31 g/cm^3.
1 ounce = 28.3495231 grams
1 cm^3 = 1000mm^3
19.31g/cm^3 x 1 ounce/28.3495231 g x cm^3/1000mm^3 =
= 4.8275 ounces/mm^3
(15.7mm)^3 = 3,869.893mm^3 x 4.8275 ounces/mm^3 = 18,681.90846 ounces x $ 125 = 2,335, 238.557 dollars...which leads me to believe this is wrong.