# algebra 2

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The amount of money in an account with continuously compounded interest is given by the formula A=Pe^rt , where P is the principal, r is the annual interest rate, and t is the time in years. Calculate to the nearest hundredth of a year how long it takes for an amount of money to double if interest is compounded continuously at 6.2%. Round to the nearest tenth.

• algebra 2 -

This means that
A/P=2, or
e^(rt)=2
log(e^(rt))=loge2
rt=loge2
t=(loge2)/r
=(loge2)/0.062 years
=?

• algebra 2 -

This means that
A/P=2, or
e^(rt)=2
log(e^(rt))=loge2
rt=loge2
t=(loge2)/r
=(loge2)/0.062 years
=?

Note:
This is actually the rule of 69.31, as follows:
The number of years to double money multiplied by the interest rate of p% compounded continuously is 69.31.

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0.3=10^06x