Which of the following measures of central tendency is least affected by extreme values?

• A. Mean
• B. Median
• C. Mode
• D. Range

Answer: (B)

The median is the measure of central tendency that is least affected by extreme values because it is determined by the middle value of a dataset when the numbers are arranged in ascending order. Unlike the mean, which can be significantly influenced by extremely high or low values, the median remains stable regardless of how extreme those values are. This characteristic makes the median particularly useful in skewed distributions where outliers might distort the overall average.

For instance, in a set of income data where most individuals earn a moderate salary but a few earn extraordinarily high amounts, the mean might suggest that individuals generally earn more than they do in reality. However, the median would give a clearer picture of the typical income by focusing solely on the middle value, thereby providing a more accurate representation of the data's central tendency.

The mode, which identifies the most frequently occurring value in a dataset, can also be influenced by extreme values if those extremes appear frequently enough. The range measures the spread of values and is highly sensitive to extremes, as it simply takes the difference between the highest and lowest values, making it unreliable when assessing central tendency in certain data sets.