Answer
Please see the work below.
Work Step by Step
We know that
$3.19\times 10^{-3}\times \frac{1 mol\space Fe}{55.85g\space Fe}=5.712\times 10^{-5}$
$Molar \space mass \space of \space \space heme=\frac{35.2\times 10^{-3}}{5.712\times 10^{-5}}=616.2\frac{g}{mol}$