Canyon Tours showed the following components of working capital last year:

Beginning of Year End of Year

Accounts receivable $ $27,000$ $ $24,500$

Inventory $13,50015,500$

Accounts payable $16,00019,500$

What was the change in net working capital during the year?

Note: A negative amount should be indicated by a minus sign.

If sales were $$37,500$ and costs were $$25,500,$ what was cash flow for the year? Ignore taxes.