Comparing Ratios

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• Comparing Ratios
• and
• Solving Proportions

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Comparing Ratios
The city of Austin, Texas, has 2 bus stops every
5 blocks.

• The city of Huston, Texas has 1 bus stop every 3
  blocks.

We can use cross products to
compare ratios.
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Comparing Ratios
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Comparing Ratios
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Comparing Ratios
When 2 ratios are equal (have the same value),
they form a proportion. We say The ratios
are proportionate.
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b c
a d
You can use cross products to solve a proportion.
You can also use cross products to check whether
two ratios form a proportion.
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Cross Products Property
Words
The cross products of a proportion are equal.
Algebra
Numbers
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EXAMPLE 1
Find x so that the ratios form a proportion.
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EXAMPLE 2
Find k so that the ratios form a proportion.