The Percent Proportion

Finding an unknown (x)in a proportion “Cross” Multiply 15x = 120 x 4 15x = 480 Solve the one step equation by dividing both sides by 15 x = 32 x 4 = 32 = 15 120

Finding an unknown (x)in a proportion “Cross” Multiply 20x = 90 x 7 20x = 630 Solve the one step equation by dividing both sides by 20 x = 31.5 x 7 = 31.5 = 20 90

Finding an unknown (x)in a proportion “Cross” Multiply 10x = 25 x 15 10x = 375 Solve the one step equation by dividing both sides by 10 x = 37.5 25 = 10 15 x = 37.5

Finding an unknown (x)in a proportion “Cross” Multiply 2x = 6 x 15 2x = 90 Solve the one step equation by dividing both sides by 2 x = 45 6 = 2 15 x = 45

What makes up a percent proportion? Part Whole Percent 100 =

Another way to remember… is of % 100 =

Finding a Part

What number is 40% of 120? % 100 is of 40 x = 120 100 100x = 120x40 100x = 4800 x = 48

What number is 12% of 72? % 100 is of 12 x = 72 100 100x = 72x12 100x = 864 x = 8.64

Finding a percent

= x 9 15 100 15x = 9x100 15x = 900 x = 60 What percent of 15 is 9? %

20 is what percent of 25 ? % 100 is of x 20 = 25 100 25x = 20x100 25x = 2000 x = 80

Finding a whole

18 is 25% of what number ? % 100 is of 25 18 = x 100 25x = 18x100 25x = 1800 x = 72

0.1% of what number is 4 ? % 100 is of 0.1 4 = x 100 0.1x = 4x100 0.1x = 400 x = 4000

106.6 60% 8 81.8% Try These 80 is 75% of what number? What percent of 5 is 3? 40% of 20 is what? 90 is what percent of 110? 60% 8 81.8%