The delesse relation in a concentrically zoned sphere. I. The section-number bias

Zonal areas of a randomly chosen section through a concentrically zoned sphere yield an estimate of the (volumetric) amount of the outer zone which is subject to a large positive bias that decreases rapidly with increase in the number of sections on which the estimate is based. It will not exceed 3% of the amount present if an analysis is based on as many as 8 sections and will be less than 1% if 32 sections are used.