Use the data developed in the table to construct the L division's free cash flows for 2005

Question:

Use the data developed in the table to construct the L division's free cash flows for 2005 through 2008. Why are we identifying interest expense separately since it is not normally included in calculating free cash flow or in a capital budgeting cash flow analysis? Why are net retentions deducted in calculating free cash flow?

Capital Budgeting
Capital budgeting is a practice or method of analyzing investment decisions in capital expenditure, which is incurred at a point of time but benefits are yielded in future usually after one year or more, and incurred to obtain or improve the... Free Cash Flow
Free cash flow (FCF) represents the cash a company generates after accounting for cash outflows to support operations and maintain its capital assets. Unlike earnings or net income, free cash flow is a measure of profitability that excludes the...