What does the standard deviation measure in a data set?

The standard deviation is a statistic that provides insight into the variability or dispersion of a data set. Specifically, it measures how spread out the data points are around the mean. A low standard deviation indicates that the data points tend to be close to the average (mean), while a high standard deviation suggests that the data points are spread out over a wider range of values. This makes the standard deviation a crucial tool in understanding the distribution of data, as it quantifies the degree of variation or consistency among the data points.

In contrast, the average value of the data points reflects central tendency, while the median represents the middle value of an ordered data set. The relationship between variables pertains to correlation or causation, which is not captured by standard deviation. Thus, the correct answer effectively highlights the fundamental role of standard deviation in assessing the spread of data in a dataset.