Which measure represents the 50th percentile?

The median represents the 50th percentile of a dataset. It is the value that divides a dataset into two equal halves, with 50% of the data points lying below it and 50% above it. In essence, when you arrange a dataset in ascending order, the median is the middle value. If there is an even number of observations, the median is calculated by averaging the two middle numbers.

The mean, on the other hand, is the arithmetic average of a set of values and does not necessarily indicate the midpoint of the data distribution, particularly when the data is skewed. Standard deviation (SD) measures the dispersion or variability of data around the mean, but it does not serve as a measure of position like the median does. Thus, the median is uniquely positioned as the measure that corresponds to the 50th percentile, effectively making it the correct answer in this context.