Answer:
Height, h = 12.27 m
Step-by-step explanation:
The pressure exerted by a column of liquid is equal to the product of the height of the column times the gravitational constant times the density of the liquid i.e.
P = d g h
Pressure, P = 713 mm column of mercury
Density, d = 0.79 g/ml = 790 kg/m³
We have to find how high a column of methanol would be supported by a pressure P. Let the height is h. So,

g = acceleration due to gravity 9.8 m/s²
We know that, 1 mm of mercury = 133.32 Pa
713 mm of mercury = 95058.9 Pa

h = 12.27 m
Hence, this is the required solution.