What is the definition of median in a list of numeric values?

The median is defined as the middle value of a sorted list of numeric values. To determine the median, you first arrange the numbers in ascending order. If the list has an odd number of values, the median is the value located exactly in the middle. For example, in the sorted list [2, 4, 6], the median is 4. If the list has an even number of values, the median is found by taking the average of the two middle values. For instance, in the sorted list [1, 3, 5, 7], the two middle values are 3 and 5, so the median is (3 + 5) / 2 = 4.

The other options pertain to different statistical concepts: the average refers to the mean or the sum of all values divided by the total number of those values, which is represented in the choice regarding sum and count; the mode refers to the value that appears most frequently in the list; hence they do not define the median accurately. Thus, the description of the median as the middle value is the correct and appropriate definition.