lowerthanaverage

Lower than average is a descriptive label used to indicate that a value, measurement, or performance metric lies below the arithmetic mean of a data set or population. The mean is computed by summing all values and dividing by the number of observations. An observation is lower than average if its value x satisfies x < μ, where μ is the mean.

This concept is sensitive to the distribution's shape. The mean can be influenced by extreme values, so a value being lower than the mean does not necessarily reflect typical performance. The median, the middle value, may provide a more robust central tendency in skewed data. In a symmetric distribution, about half of observations lie below the mean.

Applications include education, where a student’s score may be described as lower than average when it falls below the class mean; economics, where earnings below the average wage are described as lower-than-average; and quality control, where measurements below the average specification indicate underperformance relative to a baseline.

Limitations and interpretation: using the mean as a benchmark can misrepresent typical value in skewed data. Outliers can distort the mean, changing which values are considered below average. Analysts often compare to the median or to a predefined target benchmark to assess performance.