A column of water in communicating vessels 25.8 cm high counterbalances a column of diesel

A column of water in communicating vessels 25.8 cm high counterbalances a column of diesel fuel 30.0 cm high. Determine the density of the diesel

hv = 25.8 cm = 0.258 m.
ρw = 1000 kg / m ^ 3.
hd = 30 cm = 0.3 m.
ρд -?
The hydrostatic pressure of the liquid at the bottom is determined by the formula: P = ρ * g * h. Where ρ is the density of the liquid, g is the acceleration of gravity, h is the height of the liquid.
P = ρv * g * hv.
P = ρд * g * hд.
ρw * g * hw = ρd * g * hd.
ρd = ρw * hw / hd.
ρd = 1000 kg / m ^ 3 * 0.258 m / 0.3 m = 860 kg / m ^ 3.
Answer: the density of diesel fuel ρd = 860 kg / m ^ 3.