Answer
$0.60cm$
Work Step by Step
We know that
$\rho_{atm}+\rho_{water}gh_1=P_{atm}+\rho_{oil}gh_2$
This simplifies to:
$h_1=h_2(\frac{\rho_{oil}}{\rho_{water}})$
We plug in the known values to obtain:
$h_1=(7.50cm)(\frac{9.20\times 10^2Kg/m^3}{1000Kg/m^3})$
$h_1=6.9cm$
Now the height difference is given as
$h=h_2-h_1$
$h=7.5cm-6.9cm$
$h=0.60cm$
