Statistics options are available from both the List of Tables tab in the Statistics by Groups (Breakdown) dialog box and the Descriptives tab in the Statistics by Groups Results dialog box. The selections made on these tabs determine the statistics that are reported in the Summary tables of means and the Detailed two-way tables. The various statistics are described below.

N.

% N. Select this check box to compute the percentage number of observations in each group.

Sums. Select this check box to compute the sums for the dependent variables for each group.

% Sums. Select this check box to compute the percentage sums of observations in each group.

Std. devs. Select this check box to compute the standard deviations for the dependent variables for each group. Note that standard deviations are computed as the square roots of the sums of squared deviation (from the mean) divided by n-1; the resulting standard deviations are estimates of the population standard deviations.

Variances. Select this check box to compute the variances for the dependent variables for each group. The variance is computed as the sum of squared deviations (from the mean) divided by n-1; the resulting variances are estimates of the population variances.

Min & max. Select this check box to compute the minimum and maximum values for the dependent variables for each group.

Median & quartiles. Select this check box to compute the median and quartiles for the dependent variables for each group. Note that medians and quartiles are only computed for the Summary table of means option.

Std. err. of mean. Select this check box to compute the standard error of the mean for the dependent variables for each group.

Conf. limits for mean.

Percentile boundaries. Select this check box to compute the specified percentile boundaries for the dependent variables for each group. Note that you can specify what percentile boundaries to compute using the First and Second fields.