Which of the following is a source of cash?

1. a decrease in accounts receivable

2. a decrease in wages payable

3. the acquisition of a new equipment

4. the repayment of debt principal

The portion of the sale of a product that contributes to covering the cash fixed costs is referred to as

the

1. gross profit margin.

2. operating profit margin.

3. contribution profit margin.

4. net profit margin.