Question

Set up the following word problem as a proportion and solve. Show all of your work.

Answer 1

The proportion would be - 

12 / 150 = x / 225.

That is, 12 per 150, x amount per 225

To solve this proportion, you can cross multiply (multiply the values diagonally) -

12 / 150 = x /225
150x = 12(225)
150x = 2700
x = 18

18 vials are required to treat 225 people.

Hope this helps! (: