A public health study examines the distribution of body mass index (BMI) in a large population of adults. A histogram of the data shows a peak at a BMI of 24, with a long tail extending towards the higher BMI values. The calculated measures of central tendency are: mean = 28.5, median = 26.0, and mode = 24.0.
Which of the following best describes the distribution of BMI in this population?
- Normal distribution
- Negative skew
- Positive skew (correct answer)
- Bimodal distribution
Explanation: A distribution with a long tail extending to the right (higher values) is described as positively skewed. In a positively skewed distribution, the mean is pulled in the direction of the tail, resulting in the relationship: mean > median > mode. The provided values (mean=28.5 > median=26.0 > mode=24.0) are characteristic of a positive skew.