Two groups each contain five values and both total 50. Their mean is 10. That shared summary does not tell you whether the values are tightly clustered or widely separated.
Write out the values
Use these invented groups: A is 8, 9, 10, 11, 12. B is 0, 0, 10, 20, 20. Both sum to 50, but their distributions look quite different.
Place each value on a simple number line. Repeated values can be stacked. Keep the same scale for both drawings so that the visual comparison remains meaningful.
Describe before adding more statistics
Note the lowest and highest values, repeated values and empty stretches. You can see that group B reaches farther from the shared mean without needing to begin with a complicated formula.
The example does not identify which group is better. That judgement requires a question and context. A wide spread can matter differently in different situations.
Choose a summary for the question
If the task concerns consistency, a mean alone is insufficient. If it concerns a combined total, the shared total may be directly relevant.
Our discussion of mean and median offers another comparison. Summary statistics become more useful when you keep the underlying values in view long enough to notice what the summary leaves out.