If $6,000 is invested at an interest rate of 7.75% per year, compounded semiannually, find the value of the investment (in dollars) after the given number of years. (Round your answers to the nearest cent.)
(a)
6 years
$6478.62
Incorrect: Your answer is incorrect.
(b)
12 years
$

Incorrect: Your answer is incorrect.
(c)
18 years
$