<PRE><B>Question 210740</B>
Solve the problem. 
Suppose that $7000 is invested in an account where interest is compounded continuously at 3.2% per year. What is the doubling time?
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A(t) = P*e^(rt)
For doubling time:
2P = P*e^(rt)
e^rt = 2
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Your problem:
e^(0.032t) = 2
Take the natural log of both sides to get:
0.032t = ln(2)
t = [ln(2)]/0.032
t = 21.66 years
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Cheers,
Stan H. 

A)4.6 yr
B)21.7 yr
C)2.2 yr
D)0.2 yr 

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