Professional in Human Resources (PHR) Practice Exam

Standard deviation is a statistical measure that quantifies the amount of variation or dispersion in a set of values. When we talk about standard deviation, we are particularly interested in understanding how individual data points differ from the average (mean) of the dataset.

In essence, a lower standard deviation indicates that the data points are clustered closely around the mean, while a higher standard deviation suggests that the data points are spread out over a wider range of values. This information is crucial in assessing the reliability and consistency of the mean as a representative value of the dataset—a key consideration in many statistical analyses and interpretations within human resources and other fields.

The other options, while related to statistics, do not accurately define what standard deviation measures. The accuracy of the mean is not determined by standard deviation; rather, it reflects the average result. Total count of observations describes sample size but does not pertain to dispersion. Central tendency is a broader concept that refers to measures like the mean, median, and mode, which represent the center point of a dataset, rather than the variability among the scores.