Earth’s oceans have an average depth of 3800 m, a total surface area of 3.63x10⁸ km², and an average concentration of dissolved gold of 5.8x10⁻⁹ g/L.
(c) Assuming the price of gold is $1595/troy oz, what is the value of gold in the oceans (1 troy oz = 31.1 g; d of gold = 19.3 g/cm³)?