Question

Find the fourth proportional of 5, 2, and 10.​

Answer 1

Any of the four terms of a discrete geometric proportion is called a proportional fourth.

`\bold{5, 2 \: and \: 10.5}`

A geometric proportion is formed as follows:

`\bold{5 : 2 :: 10 : x}`

Since the unknown term is an extreme and as we have seen before, one extreme is equal to the means divided by the other extreme, we will have:

`\boxed{\bold{ \: x = (2 \:∗ \: 10)/(5) = 4} }`

Therefore, the geometric proportion is:

`\bold{5 : 2 :: \: :: 10 :4}`