What statistical measure is least affected by outliers?

The median is the correct choice as it represents the middle value of a data set when the values are arranged in ascending or descending order. Since it is calculated by finding the central point of the data, it does not get significantly influenced by extreme values or outliers. For example, in a data set where most values are clustered around a certain range, the presence of an extremely high or low value will not move the median as drastically as it would move the mean.

In contrast, the mean is the average of all the values, and outliers can disproportionately skew this average, often leading to a misleading representation of the data. The mode, while it may seem unaffected, can still be influenced if the outlier is a frequent occurrence, especially in small data sets. Standard deviation, which measures the spread of data around the mean, is sensitive to outliers, as they increase the overall variability of the data set. The median provides a robust measure of central tendency that remains reliable even when the data includes extreme values.