Question

Determine, if the following are in proportion:

$8,10,16,20$

Answer 1

For the ratio in proportion:

If $a:b::c:d$,

$\frac{a}{b}=\frac{c}{d}$

We have $ad=bc$

Consider the proportion, $8:10::16:20$

Product of extremes is $8\times 20=160$

Product of means is $10\times 16=160$

Thus, product of extremes is equal to product of means.

Hence, $8,10,16,20$ are in proportion.