A town has a population of 27,000 and shrinks at a rate of 8% every year. Which equation represents the town's population after 7 years?P=27,000(0.2)7P=27,000(0.92)7P=27,000(1−0.08)(1−0.08)(1−0.08)P=27,000(0.08)7
Q. A town has a population of 27,000 and shrinks at a rate of 8% every year. Which equation represents the town's population after 7 years?P=27,000(0.2)7P=27,000(0.92)7P=27,000(1−0.08)(1−0.08)(1−0.08)P=27,000(0.08)7
Identify Initial Population and Rate: We need to find the equation that represents the population after 7 years, given an initial population and a yearly decrease rate. The initial population is 27,000, and the shrinkage rate is 8% per year, which means the population retains 100%−8%=92% of its size each year. To represent this mathematically, we use the formula for exponential decay: P=P0×(1−r)t, where P0 is the initial population, r is the shrinkage rate as a decimal, and t is the time in years.
Convert Rate to Decimal: Convert the shrinkage rate from a percentage to a decimal by dividing by 100. So, 8% becomes 0.08. This means that each year, the population is 92% of the previous year's population, which is represented as 0.92 in decimal form.
Apply Exponential Decay Formula: Now, we apply the exponential decay formula with the values we have: P0=27,000, r=0.08, and t=7. The equation becomes P=27,000×(1−0.08)7, which simplifies to P=27,000×(0.92)7.
Check Correct Equation: We can now check the given options to see which one matches our equation. The correct equation that represents the town's population after 7 years is P=27,000×(0.92)7.
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