Answer
$0.832$
Work Step by Step
We know that
$\rho_1=\frac{PM}{R\times (273+79.2)}$..................eq(1)
and $\rho_2=\frac{PM}{R\times (273+20.3)}$..............eq(2)
Dividing eq(2) by eq(1), we obtain:
$\frac{\rho_1}{\rho_2}=\frac{273+20.3}{273+79.2}$
$\frac{\rho_1}{\rho_2}=0.832$
