SOLUTION: The amount of money invested in a certain account increases according to the following function, where y0 is the initial amount of the investment, and y is the amount prese

Algebra.Com
Question 1137325: The amount of money invested in a certain account increases according to the following function, where
y0
is the initial amount of the investment, and
y
is the amount present at time
t
(in years).
=yy0e0.045t
After how many years will the initial investment be doubled? Do not round any intermediate computations, and round your answer to the nearest tenth.

Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
this is the continuous compounding formula
y=yo*e^(0.045t), y/yo=e^(0.45t)
when it doubles, y/yo=2
so 2=e^(0.045t)
ln both sides
ln2=0.045t
t=15.4 years (rule of 70, where interest rate (in %)* time(years)=70 as a quick way to get a sense of doubling time.

RELATED QUESTIONS

Please help me with this problem: Richard invests $10,000.00 in a savings account which... (answered by robertb)
I kinda have an idea, but I'm confused. =_= Q1: The number of bacteria in a certain... (answered by jorel1380)
A certain radioactive substance decays according to the formula q(t)= q0e^-.0063t. where... (answered by ankor@dixie-net.com)
Where do i start to set this up? Suppose that 79,000 is invested at 5 and 1/2%... (answered by stanbon)
How long will it take any quantity of iodine 131 to decay to 25% of its initial amount,... (answered by Boreal)
Martin purchased company ABC's stock and invested the balance in his money market... (answered by stanbon)
Following the birth of their grandson, his grandparents deposit $10,000 in a college... (answered by ewatrrr)
How long will it take any quantity of iodine 131 to decay to 25% of its initial amount,... (answered by nerdybill)