Which equation correctly shows the multiplication of the means and extremes in the proportion 13⁄78 = 9⁄54? a. 13 ⋅ 9 = 78 ⋅ 54 b. 78 ⋅ 13 = 54 ⋅ 9 c. 13 ⋅ 54 = 78 ⋅ 9 d. 13 ⋅ 9 = 78 ⋅ 13

13 • 54= 78•9 is the correct answer.
When we cross multiply for proportions we put the sets of numbers in “fraction” form across from one another, then we multiply the top number from the first set by the bottom number of the second set. And the same thing for the top number of the second set and the bottom number of the first set.