Calculate IWAA

To calculate the Income-Weighted Average Age (IWAA):

1. Multiply each borrower's monthly income by their age.
2. Add the results together.
3. Divide by the total gross monthly income.

Using the scenario provided:
- John: $10,000 × 50 = $500,000
- Janet: $5,000 × 22 = $110,000
- Total: $500,000 + $110,000 = $610,000
- Total gross monthly income: $10,000 + $5,000 = $15,000

IWAA = $610,000 ÷ $15,000 = 40.67

So, the Income-Weighted Average Age is 40.67 years.