Answer: Dwayne's investment will be worth $89,961.02 after the last annuity payment is made.
Since Dwayne contributes $4700 at the beginning of each year, we need to calculate the future value of an annuity due.
We use this formula for our calculations:
[tex]\mathbf{FV _{Annuity due} = PMT * \left [ \frac{(1+r)^{n}-1}{r} \right ]*(1+r)}[/tex]
Substituting the values we get,
[tex]\mathbf{FV _{Annuity due} = 4700 * \left [ \frac{(1+0.7)^{12}-1}{0.07} \right ]*(1+0.07)}[/tex]
[tex]\mathbf{FV _{Annuity due} = 4700 * \left [ \frac{2.252191589}-1}{0.07} \right ]*(1.07)}[/tex]
[tex]\mathbf{FV _{Annuity due} = 4700 * \left [ \frac{1.252191589}}{0.07} \right ]*(1.07)}[/tex]
[tex]\mathbf{FV _{Annuity due} = 4700 * 17.88845127 *(1.07)}[/tex]
[tex]\mathbf{FV _{Annuity due} = 89961.02144}[/tex]