American Institute of Certified Planners (AICP) Practice Exam

What statistical term describes the value that separates the highest half from the lowest half?

1. Mean

2. Median

3. Mode

4. Range

The correct answer is: Median

The term that describes the value separating the highest half from the lowest half of a data set is the median. The median is the middle value in a sorted list of numbers. If the data set contains an odd number of observations, the median is the middle number when arranged in order. If there are an even number of observations, the median is calculated by taking the average of the two middle numbers. This measure of central tendency is particularly important in statistics because it is not influenced by extreme values or outliers, making it a robust indicator of the central point of a data distribution. In contrast, the mean is the average of all values in a data set and can be skewed by extremely high or low values. The mode represents the most frequently occurring value in the data set, while the range measures the difference between the highest and lowest values, neither of which specifically indicates the middle separation of data distributions. Thus, the median effectively serves as that central dividing line in a data set.