Answer: Marc should deposit $39.87 weekly.
Explanation:
We would apply the formula for determining future value involving deposits at constant intervals. It is expressed as
S = R[{(1 + r)^n - 1)}/r][1 + r]
Where
S represents the future value of the investment.
R represents the regular payments made(could be weekly, monthly)
r = represents interest rate/number of interval payments.
n represents the total number of payments made.
From the information given,
S = $4500
Assuming there are 52 weeks in a year, then
r = 0.08/52 = 0.0015
n = 52 × 2 = 104
Therefore,
4500 = R[{(1 + 0.0015)^104 - 1)}/0.0015][1 + 0.0015]
4500 = R[{(1.0015)^104 - 1)}/0.0015][1.0015]
4500 = R[{(1.169 - 1)}/0.0015][1.0015]
4500 = R[{(0.169)}/0.0015][1.0015]
4500 = R[112.67][1.0015]
4500 = 112.839R
R = 4500/112.839
R = 39.87