Suppose Amanda, Claudia and Delaney go to a donut shop. Amanda buys 6 apple crumb, 6 brown butter pecan and 2 chocolate frosted donuts and ends up spending $19.56. Claudia gets 5 of the apple crumb, 4 brown butter pecan and 2 chocolate frosted donuts for a total cost of $15.94. Lastly, Delaney spends $19.69 on 5 apple crumb, 8 brown butter pecan, and 3 chocolate frosted donuts. Write this scenario as a system of equations, then solve that system using an augmented matrix and RREF on your calculator before answering the question below. How much does a single chocolate frosted donut cost? Round your answer to 2 decimal places.