Editing Geometric mean (section)

===Financial===
The geometric mean has from time to time been used to calculate financial indices (the averaging is over the components of the index). For example, in the past the [[FT 30]] index used a geometric mean.<ref name="Rowley 1987">{{cite book |title=The Financial System Today |first=Eric E. |last=Rowley |publisher=Manchester University Press |year=1987 |isbn=0719014875 |url-access=registration |url=https://archive.org/details/financialsystemt0000rowl }}</ref> It is also used in the [[Consumer price index|CPI]] calculation<ref name=gad-201703>{{cite web |url=https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/596837/Inflation_Indices.pdf |title=Measuring price inflation |publisher=Government Actury's Department |via=gov.uk |date=March 2017 |access-date=15 July 2023}}</ref> and recently introduced "[[RPIJ]]" measure of inflation in the United Kingdom and in the European Union.

This has the effect of understating movements in the index compared to using the arithmetic mean.<ref name="Rowley 1987"/>