Question 671714
I need to find the interest rate needed for an investment of $4200 to double in 5 years if interest is compounded continuously.
**
Formula  for continuous compounding: 
A=Pe^rt, P=initial investment, r=interest rate, t=number of years, A=amt after t years
A/P=e^rt
2=e^5r
take log of both sides
ln2=5r*lne
lne=1 (log of base=1)
5r=ln2
r=ln2/5
r≈0.1386
interest rate needed for an investment of $4200 to double in 5 years if interest is compounded continuously≈13.86%