  Our previous analyses of the redshifts and distances of galaxies included 55
spiral galaxies and 36 Type Ia Supernovae galaxies in three separate groups.
All groups showed evidence that their radial velocities contain the same
discrete velocity components that are predicted from the early work of Tifft.
Here we examine another new source sample containing 83 ScI galaxies. When
B-band distances are used, we find clear evidence that the discrete velocities
defined by Tifft's most common velocity period are present in the radial
velocities of these galaxies. Assuming this is true, we are then able to use
the visibility, or ease of detection, of the discrete components as an
indication of the distance accuracy of the galaxies, comparing B- and I-band
distances, galaxy inclination ranges, and galaxy rotation velocity ranges. We
find (a), that, contrary to expectation, B-band distances for these sources are
considerably more accurate than I-band, (b), that the distance accuracy varies
with galaxy inclination, as expected, with the most consistent distances
obtained for inclinations between 48 and 65 degrees, and (c), that distances
are probably more accurate for small rotation velocities. With these results
for the 83 ScI galaxies, discrete velocity components have now been detected in
all 174 galaxies examined.
