Respuesta :

Peredhel
Hi!

4:7
x:21

21/7 = 3
4 · 3 = 12

4:7
12:21

There are 12 boys at the movie.

Hope this helps! :)
gabbycastle
If ratios aren't a strong thing for you, make it into a fraction and compare it that way.

4/7 = _/21

21 divided by 7 = 3

So, 3 times 4 = _