What can be said about a set of data when its standard deviation is small but not zero?

This means that the set of data is clustered really close to the mean/average. Your data set likely has a small range (highest value

• lowest value).

In other Words, if the average is 6.3, and the standard deviation is 0.7, this means that each individual piece of data, on average, is different from the mean by 0.7. Each piece of data deviates from the mean by an average (standard) of 0.7; hence standard deviation!

By definition, 66% of all data is 1 standard deviation from the mean, so 66% of the data in this example would be between the values of 5.6 and 7.0.