Given:
Allison made purple paint by mixing 3 parts red paint with 4 parts blue paint.
So, the ratio to made a purple paint = red : blue = 3 : 4
Chris has two fluid ounces of blue paint.
We need to match Allison's shade of purple
So, we will find how much red-painted should Chris mix with his blue paint.
We will solve by the ratio and proportions as follows:
Red : Blue
3 : 4
x : 2
Where (x) is the number of fluid ounces of red-painted.
Using the cross product, the value of (x) will be as follows:
So, the answer will be:
Chris needs 1.5 fluid ounces of red.