What is the term for the middle item in a data set when it is arranged in ascending order?

The term for the middle item in a data set when it is arranged in ascending order is the median. To find the median, you first arrange all the numbers from smallest to largest. If there is an odd number of values, the median is the value that lies exactly in the center. If there is an even number of values, the median is the average of the two middle numbers.

The median is a measure of central tendency that represents the midpoint of a data set, thus effectively dividing the dataset into two equal halves. This property makes it a robust indicator of central location, particularly useful in data sets that may contain outliers which could skew the mean.

The mean, or average, is calculated by summing all the values and dividing by the count, which can be influenced by extremely high or low values. The mode is the most frequently occurring number in a set, and the range indicates the difference between the highest and lowest values. Each of these terms describes a different statistical property, emphasizing why median is specifically used to denote the middle value.