Proportion Cross Product
Solves equivalent ratios by equating cross products.
a/b = c/d ⇒ ad = bc
Variables
- a,b,c,d
- proportional quantities
Example
3/4 = x/20 → x=15
How to use this formula
Identify the known values, keep units consistent, substitute the values into the formula, and calculate carefully. Then check whether the result is reasonable for the original problem.