Yes it is.
Jeppesen don't normally derive anything - they use the data supplied by the State authority. Different States use different methodologies.
The advisory altitudes are calculated from the TCH, so the DME distance at the runway threshold has to be calculated. The DME distance at the approach OCA is then determined using tan 3 deg function. This value is then rounded and 320ft/NM (3 deg slope) used for the subsequent DME/altitude values. It ain't rocket science.