Assessment and Learning in Knowledge Spaces (ALEKS) Practice Exam

In statistics, what would you call the middle value of a data set?

1. Mode

2. Mean

3. Median

4. Range

The correct answer is: Median

The middle value of a data set is referred to as the median. This is the value that separates the higher half from the lower half of the data set when the numbers are arranged in order. If there is an odd number of observations, the median is the number located in the middle position. If there is an even number of observations, the median is calculated as the average of the two middle numbers. Understanding the median is important as it provides a measure of central tendency that is not affected by outliers or extreme values, making it a robust indicator of the data's center. In contrast, the mean (the average of all values) can be skewed by very high or very low values. The mode refers to the value that appears most frequently in a data set, while the range measures the difference between the highest and lowest values. Each of these terms describes different aspects of data sets, but only the median specifically identifies the middle value.