Question 1035676
We will use this formula {{{A = P*(1+r/n)^(n*t)}}} where...
A = final amount in account after t years
P = principle (amount deposited)
r = interest rate in decimal form
n = compound frequency
t = time in years


In this case, 
A = Unknown. We're solving for this
P = 800 dollars is deposited
r = 0.09 (decimal form of 9%)
n = 1 (we're compounding annually, so 1 time per year)
t = 4 years


So we will plug P = 800, r = 0.09, n = 1 and t = 4 into the formula above to get...



{{{A = P*(1+r/n)^(n*t)}}}



{{{A = 800*(1+0.09/1)^(1*4)}}}



{{{A = 800*(1+0.09/1)^(4)}}}



{{{A = 800*(1+0.09)^(4)}}}



{{{A = 800*(1.09)^(4)}}}



{{{A = 800*1.41158161}}}



{{{A = 1129.265288}}}



{{{A = 1129.27}}} Round to the nearest penny



The balance after 4 years is <font color=red>$1129.27</font>


Side Note: this is assuming that no money was withdrawn or that no extra money was deposited. The account is not touched for those 4 years. Also, this is assuming the interest rate does not change over the 4 years.