Question

What must the area of a water-filled manometer be to measure blood pressures as high as 288 mm hg?

Answer 1

question should ask height, not area. area can be anything.

let height of water be h
density of water = 1000 kg/m^3
height of mercury = 288 mm
density of mercury= 13690 kg/m^3

1000 × h =13690. × 288

h = 13690×288/1000 = 3942.7mm