Measures of spread or variationdescribe the distribution of a set of datawhat are the three measures of spread?range/ variance/ standard deviationrangethe difference between the greatest and least values in a set of datavariancethe mean of the squares of the deviations from the meanstandard deviationthe average amount by which individual items deviate from the mean of all the datafrequency distributionorganized table of data that shows how often each data value or group of data values called a class or interval appears in a data setclass/intervalgroup of data valuesrelative frequencyratio of data within the class to all the dayacumulative frequencythe sum of its frequency and all previous classescumulative relative frequencythe ratio of the cumulative frequency of the class to all the dataclass widthrange of values for each classlower class limitthe smallest value within the classupper class limitthe largest value within the class