Created attachment 161310 [details]
Example with screenshot from Gnumeric
ODF 1.3 has the property chart:regression-moving-type with values "prior", "center" and "averaged-abscissa". LibreOffice 7.0 does not know this property, but always calculates as "prior", which fortunately is the default value for this property.
But especially "averaged-abscissa" is much better than "prior". Gnumeric can generate moving-average regression curves of type "averaged-abscissa". The attached file contains a screenshot from Gnumeric.
My feature request is, to implement the property chart:regression-moving-type.