Formula for amount, A, in Compound Interest:
A = P(1 + r)ⁿ
Where P = Principal = $800, r = rate per year = 7% = 0.07, n = number of years = 4
A = P(1 + r)ⁿ
A = 800(1 + 0.07)⁴
A = 800(1.07)⁴ Use your calculator
A ≈ 1048.6368
A ≈ $1048.64
I hope this helped.