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Repeated changes, weighted percentages and reverse compound growth
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Repeated changes, weighted percentages and reverse compound growth
Repeated changes, weighted percentages and reverse compound growth
Example 1
A price rises by 29% and then falls by 29%. What is the overall percentage decrease?
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Answer: 8.41
- The multipliers have product 1−(10029)2.
- Therefore the decrease is 8.41%.
Example 2
An item is discounted by 10%, then 5% tax is added to the reduced price. The final price is $2929.5. Find the original price in dollars.
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Answer: 3100
- Undo the multipliers.
- 2929.0.9×1.055=3100.
Example 3
A price rises by 13% and then falls by 13%. What is the overall percentage decrease?
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Answer: 1.69
- The multipliers have product 1−(10013)2.
- Therefore the decrease is 1.69%.
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