What is the mean proportional of 48 and 12?

The correct answer is Option (2) → 24

The mean proportional of \(a\) and \(b\) is the number \(x\) for which \(a:x=x:b\). Then \(x^2=ab\), so \(x=\sqrt{ab}\).

• Square of the mean proportional: \(x^2=48\times12=576\)

• Mean proportional: \(x=\sqrt{576}=24\)