Calculating Mean Proportional Between Two Numbers

The mean proportional (or geometric mean) between two positive numbers $a$ and $b$ is the square root of their product. It represents a number that maintains the same ratio to the first number as the second number maintains to it.

Finding the Mean Proportional

To find the mean proportional between 7.2 and 20, we use the formula:

Mean Proportional = $\sqrt{a \times b}$

Steps:

• Identify the numbers: Here, $a = 7.2$ and $b = 20$.
• Multiply the numbers: Calculate the product $a \times b$.

  $7.2 \times 20 = 144$

• Calculate the square root: Find the square root of the product.

  $\sqrt{144} = 12$

Therefore, the mean proportional between 7.2 and 20 is 12.