If I have an initial investment of $510 which compounds annually at 5% to a final amount of $1070.68, how many years did it take?
Assuming once-a-year compounding, we have
1070.68 = 510(1 + .05)N ........where N is the number of years divde both sides by 510
1070.68/510 = (1 + .05)N take the log of both sides
log (1070.68/510) = log (1.05)N and we can write
log (1070.68/510) = N log (1.05) divide sides by log (1.05)
log (1070.68/510)/log(1.05) = N = about 15.2 years
Assuming once-a-year compounding, we have
1070.68 = 510(1 + .05)N ........where N is the number of years divde both sides by 510
1070.68/510 = (1 + .05)N take the log of both sides
log (1070.68/510) = log (1.05)N and we can write
log (1070.68/510) = N log (1.05) divide sides by log (1.05)
log (1070.68/510)/log(1.05) = N = about 15.2 years