Question

Find the mean proportional between the following:

$3$ and $12$

Answer 1

Let $x$ be the mean proportion. Then $3,x,\&12$ are in continued proportion.

$b^2=ac$ $\left[b=x,a=3,\&c=12\right]$

$x^2=3\times 12$

$x=\sqrt{36}$

$x=6$

So, $6$ is the mean proportion between $3$ and $12.$