SOLUTION: Ben wants to double his money in 8 years by investing it in a savings account with interest compounded annually. What interest rate must the savings account offer in order for his

Question 773818: Ben wants to double his money in 8 years by investing it in a savings account with interest compounded annually. What interest rate must the savings account offer in order for his money to double in 8 years? (Use the formula a=p(1+i)^n)
Thanks for any help.
Answer by josgarithmetic(39618) (Show Source): You can put this solution on YOUR website!
i is assumed in decimal form. Choose a=2 and p=1. n=8 as given.
SOLVE FOR i. This will involve logarithms.

To continue, decide which base you want. Euler number, or ten. Either of them would be practical. You would want to actually solve for and then subtract 1 in order to have i.

Continuing with base-ten,

staying with just three significant figures. This means 9.05%
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