7600 dollars is placed in an account with an annual interest rate of 6.25%. To the nearest year, how long will it take for the account value to reach 16000 dollars?Answer:
Q. 7600 dollars is placed in an account with an annual interest rate of 6.25%. To the nearest year, how long will it take for the account value to reach 16000 dollars?Answer:
Identify Formula: Identify the formula to use for compound interest.The formula for compound interest is A=P(1+r/n)(nt), where:A = the amount of money accumulated after n years, including interest.P = the principal amount (the initial amount of money).r = the annual interest rate (decimal).n = the number of times that interest is compounded per year.t = the time the money is invested for, in years.Since the problem does not specify how often the interest is compounded, we will assume it is compounded annually, so n=1.
Set Up Equation: Set up the equation with the given values and solve for t. We have P=$7600, A=$16000, r=6.25% or 0.0625, and n=1. The equation becomes $16000=$7600(1+0.0625/1)(1⋅t).
Simplify and Isolate: Simplify the equation and isolate the exponential part.16000=7600(1+0.0625)t16000=7600(1.0625)tTo isolate t, we need to divide both sides by 7600.760016000=(1.0625)t
Calculate Left Side: Calculate the left side of the equation.$16000/$7600=2.10526315789 (approximately)So, 2.10526315789=(1.0625)t
Take Natural Logarithm: Take the natural logarithm of both sides to solve for t.ln(2.10526315789)=ln((1.0625)t)Use the property of logarithms that ln(ab)=b⋅ln(a).ln(2.10526315789)=t⋅ln(1.0625)
Calculate Logarithm: Calculate the natural logarithm of both sides.ln(2.10526315789)≈0.7447274949ln(1.0625)≈0.06062462182Now, divide the logarithm of the left side by the logarithm of the right side to find t.t=ln(1.0625)ln(2.10526315789)t≈0.060624621820.7447274949
Calculate Value: Calculate the value of t.t≈0.060624621820.7447274949t≈12.28Since we need to find the nearest year, we round t to the nearest whole number.t≈12 years
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