platinum metal currently costs $1700 per troy ounce ( note: this is different than a regular ounce 1 troy ounce =31.1035 g. what would the costs be, in dollars , to purchase enough platinum to form a solid cone with maximum radius 0.750 m ?

volume of cone = (1/2)*pi*r^2*h

Look up the density and use that to solve for grams(mass).

Convert grams to troy oz.

1700 x #troy oz = cost.