SOLUTION: How long will it take a $300 investment to be worth $400 if it is continuously compounded at 9% per year?

Question 509750: How long will it take a $300 investment to be worth $400 if it is continuously compounded at 9% per year?
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
How long will it take a $300 investment to be worth $400 if it is continuously compounded at 9% per year?
**
A=Pe^rt, P=$invested, r=annual rate of interest, A=amount after t years
..
400=300e^.09t
400/300=e^.09t
4/3=e^.09t
take ln of both sides
ln(4/3)=.09t*lne
log of base=1
.2877=.09t
t=.2877/.09=3.2 yrs
ans:
It will take about 3.2 years for a $300 investment to be worth $400
RELATED QUESTIONS
How long will it take a $700 investment to be worth $800 if it is continuously compounded (answered by Fombitz)

http://www.algebra.com/tutors/students/ask.mpl How long will it take a $500 investment... (answered by jim_thompson5910)

How long, to the nearest year, will it take an investment to triple if it is continuously (answered by solver91311)

How long will it take for an investment of $1000 to double in value if the interest rate... (answered by robertb)

How long it will take for an investment of 2000 dollars to double in value if the... (answered by stanbon)

How long it will take for an investment of 2000 dollars to double in value if the... (answered by graphmatics,MathTherapy)

how long will it take for $1000 to be worth $2500 at 8% interest, compounded... (answered by Alan3354)

How long will it take for an investment to triple if it is compounded continuously at... (answered by Fombitz)