Final answer:
When the variance is equal to zero, it means that all of the raw scores in the data set are the same.
Step-by-step explanation:
In statistics, variance is a measure of how spread out or dispersed a set of data points are. It provides information about the variability or the degree to which individual data points in a dataset deviate from the mean (average) of the dataset.
When the variance is equal to zero, it means that all of the raw scores in the data set are the same. Variance measures the spread or variability of the data from the mean. Therefore, if the variance is zero, it indicates that there is no variation among the data points.