algebra
posted by Anonymous .
$11,700 is invested in a compound interest account paying 3.9% compounded quarterly. How much will be in the account after 18 years? Round your answer to the nearest cent.

evaluate
11700(1 + .039/4)^72 
23527.940563

An isotope of protactinium undergoes radioactive changes at an exponential rate, having a halflife of 32,760 years. Determine the number of grams that will remain 2,000 years from a 120gram sample using the function