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You deposit $15,000\$15,000 into a savings account with an annual interest rate of 5%5\%, compounded annually. How long will it take for the account balance to grow to $25,000\$25,000? Use the formula A=P(1+rn)ntA = P\left(1 + \frac{r}{n}\right)^{nt}, where AA is the balance (final amount), PP is the principal (starting amount), rr is the interest rate expressed as a decimal, nn is the number of times per year that the interest is compounded, and tt is the time in years. Round your answer to the nearest hundredth.

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Q. You deposit $15,000\$15,000 into a savings account with an annual interest rate of 5%5\%, compounded annually. How long will it take for the account balance to grow to $25,000\$25,000? Use the formula A=P(1+rn)ntA = P\left(1 + \frac{r}{n}\right)^{nt}, where AA is the balance (final amount), PP is the principal (starting amount), rr is the interest rate expressed as a decimal, nn is the number of times per year that the interest is compounded, and tt is the time in years. Round your answer to the nearest hundredth.
  1. Identify values: Identify the values of PP, rr, nn, and AA.
    P=$15,000P = \$15,000
    r=0.05r = 0.05
    n=1n = 1
    A=$25,000A = \$25,000
  2. Substitute values in formula: Substitute P=15000P = 15000, r=0.05r = 0.05, n=1n = 1, and A=25000A = 25000 in the formula. 25000=15000(1+0.051)1t25000 = 15000(1 + \frac{0.05}{1})^{1 \cdot t} 25000=15000(1.05)t25000 = 15000(1.05)^t
  3. Divide to isolate: Divide both sides by 1500015000 to isolate (1.05)t(1.05)^t. 2500015000=(1.05)t\frac{25000}{15000} = (1.05)^t 1.6667=(1.05)t1.6667 = (1.05)^t
  4. Take natural logarithm: Take the natural logarithm (\ln) of both sides to solve for t t . ln(1.6667)=ln((1.05)t) \ln(1.6667) = \ln((1.05)^t) ln(1.6667)=tln(1.05) \ln(1.6667) = t \cdot \ln(1.05)
  5. Divide to solve for t: Divide both sides by ln(1.05)\ln(1.05) to solve for tt.\newlinet=ln(1.6667)ln(1.05)t = \frac{\ln(1.6667)}{\ln(1.05)}\newlinet0.51080.04879t \approx \frac{0.5108}{0.04879}\newlinet10.47t \approx 10.47

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