To evaluate how effectively a firm is using its fixed assets, one would look at which ratio?

The fixed asset turnover ratio is designed to assess how efficiently a company is utilizing its fixed assets to generate revenue. This ratio is calculated by dividing the company's total revenue by its net fixed assets. A higher fixed asset turnover ratio indicates that a company is effectively using its fixed assets to produce more sales, suggesting operational efficiency in asset management.

In contrast, the average payment period focuses on how quickly a company settles its short-term obligations, which does not directly relate to the usage of fixed assets. The debt ratio measures the proportion of a company's debt to its total assets, providing insights into financial leverage but not asset productivity. Lastly, while the total asset turnover ratio assesses how efficiently a firm uses all its assets to generate sales, it includes both current and fixed assets in its calculation. Therefore, the fixed asset turnover ratio is the most specific measure for evaluating the effectiveness of fixed asset utilization alone.