The following data is entered into an Excel worksheet for a one-time investment: Annual Rate of Return, cell C1, 8.5% Investment Duration, cell C2, 20 Years Investment per Month, cell C3, $400 One Time Investment, cell C4, $30,000

Write a function that will calculate the value of this investment after 20 years. Assume the investments are made at the beginning of every month. Write the function as if you were entering it into an Excel worksheet.