find the missing number to complete the porportion

Question

4 apartments on 1 floor=_______ Apartments on 5 floors

Answer 1

Let's represent these as a ratio

4 apartments on 1 floor is the same as 4/1

___ apartments on 5 floors is the same x/5

We set them equal since they are proportional

4/1 = x/5

Now we solve for x by multiply by 5 on both sides. This cancels the 5 from the right side of the equation and results in 20.

5(4/1)=x

20/1=x

20=x

The missing number is then 20.

To verify you can plug it into our ratio. if both sides result in the same, we know we got the correct answer

4/1=20/5

4=4