In a data set, if one value is much smaller than the others, which statistic is most affected?

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

Answer: (D)

The mean uses every value in the data set, so a single value that is much smaller than the others pulls the average down a lot. For example, if most numbers hover around 10, but one number is 1, the mean drops noticeably because that small value adds less to the total while still being counted in the average. The median, which is the middle value, doesn’t change much unless the outlier shifts the middle position; the mode is about the most common value and often isn’t affected by a rare outlier; and the range depends on both the smallest and largest values, so it can change, but the mean consistently reflects the influence of every data point, making it the statistic most affected by a single very small value.