Question

Find the missing value in the proportion 12/34 = 18/m.

Answer 1

Explanation:

`(12)/(34) = (18)/(m) \\ cross \: multiply \\ 12m = 612 \\ m = (612)/(12) \\ m = 51`

Answer 2

Both the top and bottom numbers would have the same scale (ratio) in order to be a proportion.

Find the scale of the top numbers:

18/12 = 1.5

The top numbers have a scale of 1.5 so the bottom numbers also have a scale of 1.5

Multiply the known bottom number by the scale:

M = 34 x 1.5 = 51