Question

Find the mean proportional of 9 and 49.

• A. 49
• B. 9
• C. 29
• D. 21

Answer 1

Answer:

D. 21

The mean proportional between two numbers (a) and (b) is:

$\sqrt{ab}$

For 9 and 49:

$= \sqrt{9 \times 49}$
$= \sqrt{441}$
= 21