2BOYS:7GIRLS=5BOYS:?GIRLS

2/7 = 5/x

2x = 35
x = 17.5

eh?

That is what I got to Steve.

To solve this proportion, we can use cross-multiplication.

The given proportion is:

2 boys : 7 girls = 5 boys : ? girls

First, cross-multiply the terms:
2 * ? girls = 7 * 5 boys

Simplify:
2 * ? = 7 * 5

Now, divide both sides of the equation by 2 to solve for "?":
? = (7 * 5) / 2

Calculating:
? = 35 / 2

The resulting calculation is a decimal value:
? = 17.5

Since the given options only include whole numbers, we need to find the whole number that is closest to 17.5. Comparing the options, we can see that the closest whole number to 17.5 is 15.

Therefore, the answer to the proportion 2 boys : 7 girls = 5 boys : ? girls is 15.