Question

Find the mean proportional of $25$ and $625$

Answer 1

Let $x$ be the mean proportional of $25$ and $625$

We have, $25:x::x:625$

$\frac{25}{x}=\frac{x}{625}$

$x^2=25\times 625$

Taking square root on both sides, we get

$x=5\times 25$

$x=125$

$\therefore 125$ is the mean proportional of $25$ and $625$