Keith is calculating the interest earned on a deposit of $2,000 in an account that earns 4.2% annual compound interest after 4 years.
- A=p(1+r)¹
- A=2,000(1+.042)⁴
- A=2,357.77

Keith determines the interest earned to be $2,357.77 as shown in his work above. Find and describe the mistake in Keith's work.

a. Find the correct amount of interest earned