Question

I can solve for the unknown value in a proportion

Answer 1

Answer:

For example:

If the 1st ratio is 3:4

And the 2nd is 9:a

You will solve it like:

3:4 :: 9:a

3:4 = 9:a

4×a = 9÷3

4a = 3

a = 4×3

a= 12

Hence, 3:4 :: 9:12