Page 74 - Math Course 3 (Book 1)
P. 74
Exponential Growth and Decay
Your Turn!
Exponential Decay
CHARITY CHARITY
A charitable organization found that the value of A charitable organization found that the value of
its clothing donations dropped by 2.5% per year. its clothing donations dropped by 2.5% per year.
Before this downturn in donations, the organization Before this downturn in donations, the organization
received clothing valued at $24,000. Write an received clothing valued at $24,000. Estimate the
equation to represent the value of the charity’s value of the clothing donations 3 years after the
clothing donations since the beginning of the start of the downturn.
downturn.
A. about $23,000
A. y = (0.975) t B. about $21,000
B. y = 24,000(0.975) t C. about $22,245
C. y = 24,000(1.975) t D. about $24,000
D. y = 24,000(0.975)
Answer
Skill Practice!
POPULATION
For Exercises 1 and 2, use the following information.
The population of New York City increased from 8,008,278 in 2000 to 8,168,388 in 2005. The annual rate of
population increase for the period was about 0.4%.
1. Write an equation for the population t years after 2000.
2. Use the equation to predict the population of New York City in 2015.
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