When to use it
Use it before every estimate, rate comparison and dashboard calculation.
When to be cautious
A correct equation can still be wrong when currencies, time periods or measurement boundaries differ.
Apply it
- Label each input with its unit, date and boundary.
- Convert explicitly and keep nominal and real price bases consistent.
- Check the resulting unit and order of magnitude.
An example in practice
A monthly throughput is divided into daily work in progress. Convert the time basis before interpreting the resulting cycle time.
Source & credit
Standard mathematical statistics; the handbook is an authoritative technical reference, not a claim of sole origin.
NIST/SEMATECH: statistical methods
This explanation and example are independently written. The source is a reading reference; linking it does not grant permission to reuse its text, figures or assessments.