I believe there should be a Section for clarification of Statistical Concept doubts.
There is a Query or Doubt for clarification:
To prepare Control Charts( using Line Graphs) in Excel or Spreadsheet.
For preparing Control Charts, 3 measures are used viz:
a) Mean
b) UCL ( Upper Control Limit) i.e. + 3 sigma
c) LCL ( Lower Control Limit) i.e. -3 sigma
This is for Reporting purpose to understand the Current Trends within a Business related Process…
All the collected data-points/ rows/ observations/ instances are over a period of time…Most Importantly, each of these Instances/ Rows are Independent of each other i.e. a different business transaction… Again all these are values ranging from 0 to + ve values in Crores/ lakhs in $…There are NO -ve values
Business Case—
There are totally 3 parameters to be considered:
a) Lab Samples in Volumes
b) Charge Entry ( raised for each procedure or business transaction at a Healthcare centre/ hospital)
c) Total Sum of Collections
For pt A, the sample is within specified range…Hence, Mean is an appropriate measure…
For pts b & c, however, both UCL & LCL are in diametrically wide- range of values ranging from -ve x,(6 zeroes) upto +ve(7 zeroes)…
Preparing Control Charts may be fine with Mean as a standard measure for Point a & generally in day-to-day normal cases…but not in the case of Points b & c (as described above).
Both — Mean ( or Arithmetic Mean) & Geometric Mean are ruled out for this particular scenario based on the outcomes. Geometric Mean is meant for Cumulative Financial Transactions
Which Statistical Measure would be appropriate in the aforesaid case:
a) Median
b) Trimmed Mean OR
c) Harmonic Mean ???
Kindly elaborate upon the reasons for doing so i.e. selection of a specified Statistical Technique???