**Let the height of the embankment be ‘h’ m **

Radius of well = 4 m

Height of the well = 14 m

Volume of earth dug out (volume of cylinder) = πr^{2}h

= \(\frac{22}7\times{4}\times{4}\times{14}\) m^{3}

= 704 m^{3}

Outer Radius of the embankment(R) = 4 m + 3 m = 7 m

Inner radius of the embankment(r) = 4 m

Volume of embankment = Volume of earth dug out

Volume of embankment = πR^{2}h - πr^{2}h

= πh (R^{2} – r^{2})

= πh (7^{2 – }4^{2 )}

= 33 πh

Volume of embankment = Volume of earth dug out

⇒ 33 πh = 704

⇒ h = \(\frac{{704}\times{7}}{{33}\times{22}}\)

⇒ h = 6.78 m