a. To calculate the present value of the future earnings if you go directly to work, we need to calculate the present value of the salary stream over the 45 years. The salary is expected to grow at a rate of 5% per year. The discount rate is 3%.
Let's break down the calculation:
Year 1:
Salary = $40,000
Present Value = $40,000 / (1 + 0.03)^1
Year 2:
Salary = $40,000 * (1 + 0.05)
Present Value = $40,000 * (1 + 0.05) / (1 + 0.03)^2
Year 3:
Salary = $40,000 * (1 + 0.05)^2
Present Value = $40,000 * (1 + 0.05)^2 / (1 + 0.03)^3
...
Year 45:
Salary = $40,000 * (1 + 0.05)^44
Present Value = $40,000 * (1 + 0.05)^44 / (1 + 0.03)^45
To calculate the present value, we sum up the present values of each year's salary:
Present Value = Σ [Salary / (1 + 0.03)^t] for t = 1 to 45
b. To calculate the present value of your future earnings if you decide to attend law school, we need to consider the salary stream starting after the 3 years of law school. The salary is expected to grow at a rate of 7% per year. The discount rate is 3%.
Let's break down the calculation:
Year 4:
Salary = $75,000
Present Value = $75,000 / (1 + 0.03)^4
Year 5:
Salary = $75,000 * (1 + 0.07)
Present Value = $75,000 * (1 + 0.07) / (1 + 0.03)^5
...
Year 42:
Salary = $75,000 * (1 + 0.07)^38
Present Value = $75,000 * (1 + 0.07)^38 / (1 + 0.03)^42
To calculate the present value, we sum up the present values of each year's salary:
Present Value = Σ [Salary / (1 + 0.03)^(t+3)] for t = 1 to 42
c. To calculate the present value of the law school tuition, we consider the payment at the beginning of each year for 3 years. The tuition is $25,000 per year. The discount rate is 3%.
Let's break down the calculation:
Year 1:
Tuition = $25,000
Present Value = $25,000 / (1 + 0.03)
Year 2:
Tuition = $25,000
Present Value = $25,000 / (1 + 0.03)^2
Year 3:
Tuition = $25,000
Present Value = $25,000 / (1 + 0.03)^3
To calculate the present value, we sum up the present values of each year's tuition:
Present Value = Σ [Tuition / (1 + 0.03)^t] for t = 1 to 3