9.5. Descriptive Statistics Tool

Figure 9-9. The Descriptive Statistics Tool Dialog.

The descriptive statistics tool calculates some statistical information of the given variables. Use this tool to calculate general statistical measures and confidence levels for mean for any number variables at the same time. The variables for which the statistical analysis is made are specified by the ``Input Range:'' entry. The given range can be grouped either by columns or by rows.

This tool can produce four different kinds of statistical data. The summary statistics is produced if the button ``Summary Statistics'' is checked. This tool calculates the mean, standard error, median, mode, standard deviation, sample variance, kurtosis, skewness, range, minimum, maximum, sum, and count for each given variable.

If ``Confidence Interval for the Mean'' button is checked, the tool calculates confidence intervals for the mean of each variable. You should specify the confidence level in the entry box. The default value is to calculate the confidence level of 95%.

Note

The interval given will usually be wider than the interval obtained using the CONFIDENCE function since that function assumes that the population standard deviation is known while this tool estimates the population standard deviation by the sample standard deviation.

If ``Kth Largest:'' button is checked, the tool finds the kth largest value of each of the variables. Specify the k in the entry box next to the check button.

If ``Kth Smallest:'' button is checked, the tool finds the kth smallest value of each of the variables. Specify the k in the entry box next to the check button.

If you have labels, for example the names of the variables, in the first row (or column) of the given range, you should check the ``Labels'' button. This leaves the first row (or column) of the input range out of the analysis. In addition, the names of the variables are printed in the output table.