Question

Use logarithms to solve the problem.

How long will it take $12,000 to grow to $17,000 if the investment earns interest at the rate of 4%/year compounded monthly? (Round your answer to two decimal places.)

yr

Answer 1

`12000 ( {1 + (.04)/(12)) }^(12t) = 17000`

`{( (301)/(300)) }^(12t) = (17)/(12)`

`12t (ln(301) - ln(300) ) = ln(17) - ln(12)`

`t = ( ln(17) - ln(12) )/(12( ln(301) - ln(300) )) = 8.72 \: years`