Below is the income statement for DEF Enterprises for the fiscal year ending December 31, 2023:

+-----------------------------------+-------------------+
|          **Revenue**             |                   |
+-----------------------------------+-------------------+
| Sales Revenue                     | $850,000          |
| Interest Income                   | $15,000           |
| Total Revenue                     | $865,000          |
+-----------------------------------+-------------------+
|          **Expenses**            |                   |
+-----------------------------------+-------------------+
| Cost of Goods Sold                | $300,000          |
| Operating Expenses                | $250,000          |
| Depreciation Expense              | $40,000           |
| Interest Expense                  | $20,000           |
| Income Tax Expense                | $70,000           |
| Total Expenses                    | $680,000          |
+-----------------------------------+-------------------+
|          **Net Income**          | $185,000          |
+-----------------------------------+-------------------+

1. Compute the gross profit margin and explain its significance in assessing the company's profitability.
2. Analyze the operating profit margin and discuss its importance in evaluating operational efficiency.