Behavior of the propagated variances after resampling a pixel table with pure random data of unit variance into a datacube. Upper left panel: single wavelength plane of this cube; the same plane of the corresponding variance cube is shown below. Upper right panel: histograms of the resampled random data evaluated over a subcube of 320 planes (400 Å) bandwidth, together with Gaussian fits to these histograms. Each of the colored curves represent a different subset of voxels selected by a specific range of the propagated variances in these voxels, as indicated by the labels. Lower right panel: histogram of the propagated variances, for the same subcube. The colored horizontal bar in the top indicates the selected variance ranges.