HSA 2006 Algebra/Data Analysis Item 16
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- CIDde319febffc33de7689c2b4c815a9cf7
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- 16
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- NA
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- 3
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- x
Erin used the equation below to model the price (y) of postage stamps, in cents, between 1950 and 1995. In Erin's model, x represents the number of years since 1950.
y = 0.014x² + 0.09x + 1.28
The graph below models the price of postage stamps, in cents, between 1950 and 1995.
Complete the following in the Answer Book:
- According to the model, when was the price of a postage stamp 29¢? Use mathematics to explain how you determined your answer. Use words, symbols, or both in your explanation.
- According to the model, what was the cost of postage stamps in 1970? Express your answer to the nearest cent. Use mathematics to explain how you determined your answer. Use words, symbols, or both in your explanation.