Which graphical representation demonstrates a variable that clusters around the mean?

• A. Skewed distribution
• B. Bell curve
• C. Normal distribution curve
• D. Uniform distribution

Answer: (C)

Clustering around the mean is a hallmark of the normal distribution curve. This curve is symmetric and unimodal, with the highest point at the mean, meaning most observations fall near the center and fewer occur as you move away from it. That central concentration is what creates the familiar bell shape and reflects the 68-95-99.7% rule, where most data lie within one, two, or three standard deviations of the mean. A skewed distribution would pile up on one side, and a uniform distribution would have values spread evenly across the range with no central clustering. The term bell curve is the common name for this shape, while the normal distribution curve is the precise description.