Statistical measures

The following table gives an overview of the available statistical measures. In column Calculation a hint is given, how the measuere is calculated from the basic data rows.

Name Abbr. Calculation
Lower range limit (human estimate) - x1..xn sorted list: x1
Upper range limit (human estimate) + x1..xn sorted list: xn
Central or typical value (human estimate) centr. x1..xn sorted list: xn/2
Lower range limit (legacy data stat. meth. unknown) -(?) x1..xn sorted list: x1
Upper range limit (legacy data stat. meth. unknown) +(?) x1..xn sorted list: xn
Central or typical value (legacy data stat. meth. unknown) centr.(?) x1..xn sorted list: xn/2
Minimum value Min Absolute smallest value
Maximum value Max Absolute largest value
Mean (= average) μ μ=(1/n)∑(n)xi
Harmonic mean hμ=n/(∑(n)(1/xi))
hμ=0 if any xi=0
Geometric mean gμ=n√∏(n)xi
Mode mode Value that appears most often (ambigious!)
Median med. x1..xn sorted list
n odd: med=x(n+1)/2
n even: med=(xn/2+x(n/2+1))/2
Interquartile mean (= average) IQM x1..xn sorted list
IQM=μ(x0.25n+1..x0.75n+1)
Variance (sample df = n-1) Var. Sn-1=(1/n-1)∑(n)(xi-μ)2
Variance (population; df = n; rarely applicable!) Var. (pop.) Sn=(1/n)∑(n)(xi-μ)2
Standard deviation (sample) s.d. σn-1=√Sn-1
Standard deviation (population; df = n; rarely applicable!) s.d. (pop.) σn=√Sn
Mean deviation m.d. md=(1/n)∑(n)|xi-μ|
Mean deviation from median m.d.m. mdm=(1/n)∑(n)|xi-med|
Coefficient of variation (sample) CV CV=σn
Corrected coefficient of variation (sample) CVC CVC=σn-1
Total range TR x1..xn sorted list
TR=xn-x1
Interquartile range IQR x1..xn sorted list
IQR=x0.75n+1-x0.25n+1
Standard error of mean s.e. σxn-1/√n
Standard error of variance (of multiple samples) s.e.(var.) Sx=Sn-1/n
Skewness Skw. ϒ1=(1/n)∑(n)((xi-μ)/σ)3
Kurtosis Kurt. Kurt=(1/n)∑(n)((xi-μ)/σ)4
Sample size n Number of values

 

Adjust display sequence

You may adjust the display sequence of the statistical measures for the whole database. Choose Administation -> Database -> Statistical measures ... from the menu. A window will open as shown below.

  

The sequence number column ("No.") determines the display sequence in various forms. You may order the entries by clicking on a column header. With the arrow buttons ( ) you can move the selected entries up or down within the table, clicking button or shifts the selected entries to the top respective bottom of the table. After ordering the entries click button to renumber the table entries (starting with "1" for the first table entry) and make the changes effective. To save the changes in the database, leave the form with the OK button, to discard all changes click the Abort button.