User Guide

553
Ratio Statisti
cs
Ratio Statis
tics
Figure 39-2
Statistics dialog box
Central Tend ency. Measures of central tendency are statistics that describe the
distribution of ratios.
 Median. The value such that the number of ratios less than this value and the
number of ratios greater than this value are the same.
 Mean. The result of summing the ratios and dividing the result by the total
number of ratios.
 Weighted mean. The result of dividing the mean of the numerator by the mean of
the denominator. It is also the mean of the ratios weighted by the denominator.
 Confidence intervals. This displays confidence intervals for the mean, the median,
and the weighted mean (if requested). Specify a value greater than or equal to 0
and less than 100 as the confidence level.
Dispersion. These are statistics that measure the amount of variation, or spread,
in the observed values.