How would you calculate the density of methanol (CH_3OH)?

And of course, $\rho , \text{density}$ $=$ $\text{Mass"/"Volume}$.
For methanol at $298 K$, $\rho = 0.792 \cdot g \cdot c {m}^{-} 3$.
Methanol is immiscible with petroleum ether, $\rho = 0.653 \cdot g \cdot c {m}^{-} 3$. Would methanol float or sink on/in pet. ether?