A new car is purchased for 22100 dollars. The value of the car depreciates at 5.25% per year. To the nearest tenth of a year, how long will it be until the value of the car is 12600 dollars?Answer:
Q. A new car is purchased for 22100 dollars. The value of the car depreciates at 5.25% per year. To the nearest tenth of a year, how long will it be until the value of the car is 12600 dollars?Answer:
Determine depreciation type: Determine the type of depreciation. The car depreciates at a constant percentage each year. This indicates exponential decay.
Identify values: Identify the initial value (a), the rate of depreciation (r), and the final value (P(t)).Initial value (a) = $22,100Rate of depreciation (r) = 5.25% or 0.0525 (as a decimal)Final value (P(t)) = $12,600
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 value, and r is the rate of decay.
Substitute values: Substitute the known values into the formula.$12,600=$22,100×(1−0.0525)t
Solve for t: Solve for t.First, divide both sides by $22,100 to isolate the exponential part of the equation.$12,600/$22,100=(1−0.0525)t0.5697≈(0.9475)t
Take natural logarithm: Take the natural logarithm of both sides to solve for t.ln(0.5697)=ln((0.9475)t)ln(0.5697)=t⋅ln(0.9475)
Divide by ln: Divide both sides by ln(0.9475) to solve for t.t=ln(0.9475)ln(0.5697)t≈ln(0.9475)ln(0.5697)t≈−0.0542−0.5621t≈10.373
Round to nearest tenth: Round the answer to the nearest tenth of a year.t≈10.4 years
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