From $1946$ to $1970,75,000kg$ of mercury was discharged into a lake in New York. The lake has a surface area of $4\mathrm{.}5m{i}^2$ and an average depth of $35ft.$ What mass $($in $g)$ of mercury is contained in each $mL$ of lake water in $1970?$ Is $6\mathrm{.}04$ x $10^-7$ the correct answer?