How is the range of a data set defined?

The range of a data set is defined as the difference between the smallest and largest values in that set. To determine the range, you first identify the minimum value and the maximum value in the data set. By subtracting the minimum value from the maximum value, you obtain the range, which provides insight into the spread or dispersion of the values within the set. This measure helps to understand how much variation exists among the data points, indicating whether the values are closely grouped together or widely spread apart.

The other options describe different statistical concepts: one option refers to the total number of items, which conveys the size of the data set rather than its variability. Another option involves the mean, which is the average of all values and highlights central tendency rather than range. The last option speaks to the average of the middle terms, which is related to the median, a measure also focused on central tendency but not on the spread of values. Thus, the correct choice precisely identifies the concept of range in the context of a data set.