SOLUTION: How long does it take for $1425 to double if it is invested at 7.5% compounded continuously? Round your answer to two decimal places, if necessary.

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Question 1140177: How long does it take for $1425 to double if it is invested at 7.5% compounded continuously? Round your answer to two decimal places, if necessary.

Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!

+F+=+Pe%5E%28rt%29+


r = annual interest rate (as a decimal value)
t = number of years
P = present value
F = future value


The problem can be solved without using $1450, as it is the same doubling time
for any starting principal (the P's cancel):

+2P+=+Pe%5E%280.075t%29+

++ln%282%29+=+0.075t+

++t+=+ln%282%29%2F0.075+ or about 9.24 years (approx 9 years 3 months)