A new car is purchased for 22300 dollars. The value of the car depreciates at 12.25% per year. To the nearest tenth of a year, how long will it be until the value of the car is 3700 dollars?Answer:
Q. A new car is purchased for 22300 dollars. The value of the car depreciates at 12.25% per year. To the nearest tenth of a year, how long will it be until the value of the car is 3700 dollars?Answer:
Determine type of depreciation: Determine the type of depreciation. The car depreciates at a constant percentage each year. This is an example of exponential decay.
Identify values: Identify the initial value a, the rate of depreciation r, and the final value P(t). Initial value, a=$22,300 Rate of depreciation, r=12.25% or 0.1225 in decimal form Final value, P(t)=$3,700
Set up formula: Set up the exponential decay formula.The formula for exponential decay is P(t)=a×(1−r)t, where P(t) is the value after time t, a is the initial amount, and r is the rate of decay.
Substitute values: Substitute the known values into the formula.$3,700=$22,300×(1−0.1225)t
Solve for t: Solve for t.First, divide both sides by $22,300 to isolate the exponential expression.(1−0.1225)t=$22,300$3,700
Calculate division: Calculate the division on the right side of the equation.(1−0.1225)t=0.1659192825
Take natural logarithm: Take the natural logarithm of both sides to solve for t.ln((1−0.1225)t)=ln(0.1659192825)t⋅ln(1−0.1225)=ln(0.1659192825)
Calculate logarithms: Calculate the natural logarithms.t⋅ln(0.8775)=ln(0.1659192825)t⋅(−0.132289)=−1.797
Solve for t: Solve for t by dividing both sides by ln(0.8775).t=−0.132289−1.797
Calculate division: Calculate the division to find the value of t.t≈13.584
Round to nearest tenth: Round t to the nearest tenth of a year.t≈13.6 years
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