Which concept can be used to demonstrate a variable that clusters around the mean?

• A. Variance
• B. Median
• C. Mode
• D. Normal distribution curve

Answer: (D)

The normal distribution curve is the best way to illustrate a variable clustering around the mean. It shows a symmetric, bell-shaped pattern with the highest frequency at the mean, meaning most observations lie near the center and the numbers taper off as you move away. This visualization directly communicates the idea of concentration around the mean, which is what you’re looking for.

Variance measures how spread out the data are, but it’s just a number describing spread, not a pattern you can see. Median and mode are about the center value, and in a normal distribution they align with the mean, but they don’t convey how data cluster around that center. The normal curve, with the 68-95-99.7% rule, explicitly depicts that clustering around the mean.