A proportion is an equation stating that two ratios are equal (two equivalent fractions)
Finding the missing value in a proportion means finding the missing value for two equivalent fractions.
There are three ways to solve proportions
Method 1: Vertical
Since 2 x 3 = 6, then 10 x 3 = 30. So the missing value is 30.
Method 2: Horizontal
Since 2 x 5 = 10, then 6 x 5 = 30. So the missing value is 30.
Method 3: Cross-products
Cross multiply and solve for X.
The missing value is 30.
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Solving Proportions by Cross Multiplication
In a proportional relationship such as
we can multiply the numerator of each side by the denominator of the other side.
The cross products of a proportion are equal. This property help us solve for an unknown value.
Solving proportions worksheets with an unknown variable (using only integers):
Proportions
What is a Proportion
Means Extreme Property
Finding X in a Proportion 1
Finding X in a Proportion 2
Finding X in a Proportion 3
Finding X in a Proportion 4
Finding the Missing Denominator
Finding the Missing Numerator
PP10 Proportion_I1
PP11 Proportion_I2
PP12 Proportion_I3
PP13 Proportion_I4
PP14 Proportion_I5
PP15 Proportion_I6
PP16 Proportion_I7
PP17 Proportion_I8
PP18 Proportion_I9
PP19 Proportion_I10
Solving proportions worksheets with an unknown variable (with one decimal):
PP20 Proportion_D1
PP21 Proportion_D2
PP22 Proportion_D3
PP23 Proportion_D4
PP24 Proportion_D5
PP25 Proportion_D6
PP26 Proportion_D7
PP27 Proportion_D8
PP28 Proportion_D9
PP29 Proportion_D10
PP30 Proportion_D11
PP31 Proportion_D12
If one term of a proportion is not known, we can use cross multiplication to find its value.