Which distribution best describes typical quality-of-life (QoL) data?

• A. Right-skewed
• B. Left-skewed
• C. Uniform
• D. Normal

Answer: (B)

Quality-of-life data measured on a bounded scale (for example, 0 to 100) often cluster toward higher values, with fewer people scoring very low. This creates a left-skewed distribution: most observations sit on the high end while a tail extends toward the low end. In such data, the mean tends to be pulled downward by the lower scores, while the median sits higher.

A right-skewed pattern would imply more low scores with a tail toward higher values, which isn’t as typical for QoL measures. A uniform distribution would mean every score is equally likely, which doesn’t reflect the common clustering of QoL scores. A normal distribution assumes symmetry around the mean, which bounded QoL scales and real-world clustering toward higher QoL often violate.