First, ratios are in the form of:
n:n (where 'n' equals any number)
While proportions are:
n(1)/n(2) = n(1`)/n(2`) (where n(1) is able to be multiplied/divided by a number to reach n(1`) (and vice versa for n(2) and n(2`)))
Now, on to the problem!
First, to be proportional means that the numbers are the same, just in different forms. This means that 3/1 and 24/8 must be the name number to be a proportion.
A simple way of doing that is to take the fraction's numerator and divide it by its denominator, and do it for all the listed fractions.
3/1 = 3
24/8 = 3
If all of the fractions simplify to the same number, then they are proportional.
3 = 3
Thus, 3/1 is proportional to 24/8