Question

After five years of earning interest at an annual rate of 4%, an interview has earned $1,200 interest.Determine the amount of the initial investment.

Answer 1

"an interview has earned $1200 in interest?"  Perhaps you meant, "A certain individual..."

i = p* r* t
                                               $1200
$1200 = p*(0.04)(5)  =>  p = ----------- = $6000 (answer)    
                                                0.20

Answer 2

Is it simple or compound interest? With simple interest, the person above would be correct. However, if it were compound interest, things get more complex.
$1.04^{5}$*n=1200+n
$1.04^{5}$n - n =1200
1200/$1.04^{5}$n - n = 5538.81 to the nearest decimal place