Explanation of Statistics

The sum of all weight values in a column. (See Column Properties in The Column Info Window.) Or, if no column is assigned the weight role, Sum Wgt is the total number of nonmissing values.

Variance

The sample variance, computed for the nonmissing values. It is the sum of squared deviations from the mean, divided by the number of nonmissing values minus one.

Std Err

The standard error of the mean. It is the standard deviation divided by the square root of N. If a column is assigned the role of weight, then the denominator is the square root of the sum of the weights.

CV (Coefficient of Variation)

The measure of dispersion, which is the standard deviation divided by the mean multiplied by one hundred.

Median

The 50th percentile, which is the value where half the data are below and half are above or equal to the 50th quantile (median).

Geometric Mean

The nth root of the product of the data. For example, geometric means are often used to calculate interest rates. The statistic is also helpful when the data contains a large value in a skewed distribution.

Note: Negative values result in missing numbers, and zero values (with no negative values) result in zero.

Interquartile Range

The difference between the third and first quartiles.

Quantiles

the value at which the specific percentage of the argument is less than or equal to. For example, 75% of the data is less than the 75th quantile. The summary window has an edit box for entering the quantile percentage that you want.

Histogram

Generates histograms for different groups. Images of the histograms are saved in data table Expression columns.