Question: how to calculate weighted average life of a portfolio?
Answer: Year 1 = 1 x $1,000 = $1,000.
Year 2 = 2 x $2,000 = $4,000.
Year 3 = 3 x $4,000 = $12,000.
Year 4 = 4 x $6,000 = $24,000.
Year 5 = 5 x $10,000 = $50,000.