Final answer:
The future value of Darnell Johnson's retirement plan is $21,225.72 assuming a 5% interest rate and $31,601.80 assuming an 8% interest rate, after 10 years. The difference between the two values is $10,376.08.
Step-by-step explanation:
To find the future value of Darnell Johnson's retirement plan, we need to calculate the contributions made by his employer and himself over 10 years, taking into account the interest earned. Let's calculate the future value assuming the funds earn 5% compounded semiannually:
Calculate the contribution made by Darnell's employer each year: 4% of $38,400 = $1,536.
Calculate Darnell's own contribution each year: 1% of $38,400 = $384.
Calculate the future value of the contributions and interest earned after 10 years using the compound interest formula: Future Value = P(1 + r/n)^(nt), where P is the 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.
Here, P = $1,536, r = 5% (or 0.05), n = 2 (semiannually compounded), and t = 10 years. Plugging in these values, we get Future Value = $1,536(1 + 0.05/2)^(2*10) = $21,225.72.
Similarly, we can calculate the future value assuming the funds earn 8% compounded semiannually:
Calculate the contribution made by Darnell's employer each year: $1,536.
Calculate Darnell's own contribution each year: $384.
Calculate the future value using the same formula as before, but with a different interest rate: Future Value = $1,536(1 + 0.08/2)^(2*10) = $31,601.80.
The difference between the two future values is $31,601.80 - $21,225.72 = $10,376.08.