Final answer:
A residual scatter plot where spots are randomly dispersed indicates that the statistical model is appropriate and unbiased, suggesting that the model's errors are random with no systematic pattern.
Step-by-step explanation:
When evaluating a residual scatter plot, if the spots are randomly dispersed, it indicates that the statistical model is appropriate and unbiased (B). This suggests that the model does a good job at predicting the response variable and that the residuals (differences between observed and predicted values) are spread randomly around zero without any systematic pattern. Such a pattern in the residuals means that the model's errors are random and do not follow a certain trend that could be further modeled.
A residual scatter plot with no discernible pattern suggests that there is no heteroscedasticity or other systematic errors that the model is missing. Therefore, this can be seen as an indication that the model is correctly capturing the relationship between the variables. However, always remember to consider the context and other diagnostic plots or statistics to confirm the model's appropriateness.