Final answer:
Marvin will need approximately 34 years to reach his goal of accumulating $1,000,000 in his retirement plan.
Step-by-step explanation:
To calculate the time it will take for Marvin to reach his goal, we can use the formula for compound interest:
A = P(1 + r/n)^(nt)
Where A is the final amount, P is the initial principal, r is the annual interest rate, n is the number of times interest is compounded per year, and t is the number of years.
In this case, Marvin's goal is $1,000,000, his monthly contribution is $250, the annual interest rate is 10.8%, and interest is compounded monthly (so n = 12).
Since we want to find t, we can rearrange the formula:
t = log(A/P) / (n * log(1 + r/n))
Plugging in the values, we get:
t = log(1000000/250) / (12 * log(1 + 0.108/12))
t ≈ 33.83 years
Since we need to round up to the nearest whole year, it will take 34 years for Marvin to reach his goal.