$1800 is invested at 10% compounded quarterly for four years. Find the amount at the end of four years. My answer is $2520.00 thanks for looking over this problem.

Hello, kwtolley!
This is NOT the formula for the problem you gave.A=R[(1+i)^n-1 / i]
A=value of the annuity after n payments
n=number of payments
i=periodic interest rate
R=amount of each periodic payment
That is for an Annuity, where payments are made in the account periodically.
You problem had a one-time investment of $1800 which is left unchanged for four years.
{What you're doing is using the Distance Formula to find the price of eggs . . . ]