What is the term for a value that appears most frequently in a data set?

The correct term for a value that appears most frequently in a data set is the mode. In statistics, the mode is a measure of central tendency, which is used to indicate the most common value within a given dataset. Identifying the mode can be particularly useful in analyzing categorical data, where it helps identify the most popular category or most frequently occurring item.

The mean, or average, represents the sum of values divided by the number of values, making it sensitive to extreme values or outliers. The median indicates the middle value when the data set is ordered, which provides a different perspective, especially in skewed distributions. The range, on the other hand, signifies the difference between the highest and lowest values in the dataset, giving an indication of the spread but not the frequency of specific values. Thus, the mode is unique in that it focuses specifically on frequency, making it the correct answer in this context.