Supported Statistics

QWXL 3 performs 100 separate statistical calculations on your data, and displays the results in the Statistics Box. These results can also be copied to the Windows clipboard and pasted into Excel®, Microsoft Word, or any other program.

Statistics Screen in QWXL3

Available Statistics in QWXL3

Below is a sample of some of the statistics available in QWXL3

Statistic Abbrev. Explanation
Number of Points N The number of non-null values found in the data selected.
Target Deviation T-Dev The separation between the average and the Target
value of the variable.
Standard Deviation – Population SD-Pop The square root of the average of the squared distances of the observations from the mean.
Standard Deviation – Low SD-Low The lowest segmented SD over a given range of data values.
Standard Deviation – Moving Range SD-MR Average Range of all points * 1.128
Maximum Max The greatest value of the selected data.
Average +4S X+4S Average of all data points plus 4 X the selected SD method
Average +3S X+3S Average of all data points plus 3 X the selected SD method
Average X The mathematical average of all data points selected.
Average -3S X-3S Average of all data points less 3 X the selected SD method
Average -4S X-4S Average of all data points less 4 X the selected SD method
Minimum Min The lowest value of the selected data.
Average Moving Range Avg-MR Average of range between all data points.
Median Med The middle value of the data set, once numerically sorted.
Observed % O%OSL The percentage of points outside of fixed spec limits.
Observed PPM OppmOSL The number of points outside of fixed spec limits, expressed in parts per million.
Calculated % C%OSL The percentage of points outside of +/- 4SD under the normal curve.
Calculated PPM O.O.L CppmOSL The number of points outside of +/- 4SD under the normal curve, expressed in parts per million.
Variation Cr The capability ratio describes the size of the process variability relative to the size of the specification range.
Targeting Tz This is determined by dividing the standard deviation into the Target Deviation. This produces a number that measures how well the process is centered on target in standard deviations.
Clearance Cpk Capability Clearance describes the clearance between the process distribution curve and the specification limits in terms of standard deviation.
Coefficient Variation %CV SD divided by average – used to normalize SD so it can be compared to other variables.