Proportions & Ratios
CONCEPTS
Proportions & Ratios
• Fractions or proportions and ratios are represented differently, but mean the same thing
(Example: 5 : 2 = 5 / 2)
There are 3 ways to represent a proportion or ratio
All examples below: There is a ratio of 5 apples : 2 oranges
• Standard ratio
(Example: In another batch, how many apples are there if there are 4 oranges => 5 / 2 = x / 4 & 5 : 2 = x : 4)
• Ratio with a total
(Example: If the total cost for all apples and oranges is $10, how much is it for apples? => 5 apples / 7 fruit = $x apples / $10 total & 5 : 7 = x : 10)
• 2+ variable equation
(Example: If 1) there are the same number of apples and oranges and 2) the total cost for all apples and oranges is $10, how much is it for apples? => 5x + 2x = $10)
ACT PRACTICE PROBLEMS