Gianna is going to invest $9,000 and leave it in an account for 17 years. Assuming the
interest is compounded daily, what interest rate, to the nearest tenth of a percent,
would be required in order for Gianna to end up with $23,300?

Respuesta :

Answer:

5.6% to nearest tenth.

Step-by-step explanation:

Amount after 17 years

= 23300 = 9000(1 + r/365)^(17*365)  where r  = interest rate as a fraction.

(1 + r/365)^(17*365) = 23300/9000 = 2.588889

Taking logs of both sides:

17*365 log (1 + r/365) =  log 2.588889

log(1 + r/365) = log 2.588889 / (365*17)

log(1 + r/365) = 0.0000665775

Removing the logs  (by taking each side to the base 10) :

1 + r/365 = 1.000153312

r/365 = 0.000153312

r = 0.05596

As a percent this is 5.596%