Which procedure can be used to detect proportional error in a new method for glucose?

The procedure of adding a known amount of glucose to a serum sample of known concentration and measuring the result is effective for detecting proportional error in a new glucose measurement method. This approach allows for a systematic way to evaluate the accuracy of the method across a range of concentrations. By using a serum sample where the concentration is already established, any deviation from the expected result after the glucose addition can indicate a proportional error in the measurement method.

When the goal is to assess how well a new method correlates with an established method, especially for proportional error, direct manipulation and comparison of known quantities provide clear insights. In this case, adding a specific amount of glucose creates a predetermined concentration, allowing the analyst to assess whether the new method underestimates or overestimates the glucose concentration as it scales.

Other approaches, while valid in their own contexts, do not specifically address proportional error in the same way. Comparing standard deviations, measuring mixtures, or comparing means do not directly isolate the effect of method error on known glucose levels, making them less effective for this particular evaluation of proportional error.