What does standard deviation indicate in a data set?

The standard deviation is a measure of the dispersion or variability within a data set. It quantifies how much the individual data points deviate from the mean (average) value. A low standard deviation indicates that the data points tend to be close to the mean, whereas a high standard deviation suggests that the data points are spread out over a wider range of values. By measuring this variability, standard deviation helps to assess the consistency of the data and gives insights into the distribution of values.

This means that option C accurately reflects the role of standard deviation in characterizing how much variability exists in the data set relative to the average. Understanding this concept is crucial for various applications in statistics, as it allows one to interpret data patterns and make informed decisions based on the spread of the data.