To find 80% of a $200 phone bill using equivalent ratios, you can follow these steps:
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Understand Percentage as a Ratio: First, recognize that 80% can be expressed as the ratio of 80 to 100. In mathematical terms, this is written as \( \frac{80}{100} \).
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Set Up an Equivalent Ratio: We want to find out how much 80% of $200 is, which can be expressed using an equivalent ratio. You can set this up as follows: \[ \frac{80}{100} = \frac{x}{200} \] Here, \( x \) represents the amount you want to find, which is 80% of $200.
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Cross-Multiply: To solve for \( x \), cross-multiply the two ratios: \[ 80 \times 200 = 100 \times x \] This simplifies to: \[ 16000 = 100x \]
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Solve for \( x \): To isolate \( x \), divide both sides by 100: \[ x = \frac{16000}{100} = 160 \]
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Conclusion: Therefore, 80% of a $200 phone bill is $160.
By using the concept of equivalent ratios, you can effectively find percentages of any amount!
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