What is the median in a set of numbers?

The median of a set of numbers is defined as the middle number when the numbers are arranged in either ascending or descending order. If the set contains an odd number of values, the median is simply the value in the center. If the set has an even number of values, the median is calculated by taking the average of the two middle numbers. This definition emphasizes the position of the values in the data set rather than their actual numerical values or frequency of occurrence, which is why the choice describing the median as the middle number is correct.

In contrast, other options describe different statistical concepts. The first number in the set does not necessarily represent its central tendency and can vary widely. The average of all terms in the set refers to the mean, which calculates the sum of all values divided by their count. The most frequently occurring number in the set is known as the mode and focuses on frequency rather than positional order. Understanding these distinctions helps clarify why the median is defined specifically as the middle value.