Final answer:
You would have more confidence in a prediction for relationship A due to its lower standard error (Sy/x = 4.00) compared to relationship B (Sy/x = 5.25).
Step-by-step explanation:
When comparing the standard error of the estimate (Sy/x), the lower value indicates a tighter fit of the data points to the regression line, which in turn suggests more reliable predictions. In this case, since relationship A has a Sy/x of 4.00 and relationship B has a Sy/x of 5.25, you would have more confidence in a particular prediction for relationship A because of its lower standard error of the estimate.