Find the time required for an investment of 5000 dollars to grow to 7100 dollars at an interest rate of 7.5 percent per year, compounded quarterly.
Your answer is t=?
:(

Question

Find the time required for an investment of 5000 dollars to grow to 7100 dollars at an interest rate of 7.5 percent per year, compounded quarterly. 
Your answer is t=?
:(

anonymous · Answer

5000=5000*.075*t

anonymous · Answer

helped??

anonymous · Answer

well??

anonymous · Answer

no it wasnt it:( at least for what i solved for..

dumbcow · Answer

7100 = 5000(1+(.075/4))^4t
7100 = 5000(1.01875)^4t
1.42 = 1.01875^4t
ln(1.42)/ln(1.01875) = 4t
18.876 = 4t
4.719 = t

dumbcow · Answer

you get it?

anonymous · Answer

actually it said it was wrong..

anonymous · Answer

your prob close though

dumbcow · Answer

haha no its right i just verified it
t = 4.71912 years

anonymous · Answer

no it is not right because it said compounded quarterly not continuously.
formula is 
$$5000(1+\frac{.075}{4})^{4y}$$

anonymous · Answer

then you solve $$7100=5000(1.01875)^{4t}$$ 
$$1.42=(1.01875)^{4t}$$
$$\ln(1.42)=4t\ln(1.01875)$$
$$t=\frac{\ln(1.42}{4\ln(1.01875)}$$

anonymous · Answer

oops dumb cow had it i only looked at first one. sorry