We have extended the discussion of Paper II ( Ekholm et al . [ 1999a ] ) to cover also the backside of the Local Supercluster ( LSC ) by using 96 galaxies within \Theta < 30 \degr from the adopted centre of LSC and with distance moduli from the direct B-band Tully-Fisher relation .
In order to minimize the influence of the Malmquist bias we required \log V _ { \mathrm { max } } > 2.1 and \sigma _ { B _ { T } } < 0.2 ^ { \mathrm { mag } } .

We found out that if R _ { \mathrm { Virgo } } < 20 \mathrm { Mpc } this sample fails to follow the expected dynamical pattern from the Tolman-Bondi ( TB ) model .
When we compared our results with the Virgo core galaxies given by Federspiel et al .
( [ 1998 ] ) we were able to constrain the distance to Virgo : R _ { \mathrm { Virgo } } = 20 - 24 \mathrm { Mpc } .

When analyzing the TB-behaviour of the sample as seen from the origin of the metric as well as that with distances from the extragalactic Cepheid PL -relation we found additional support to the estimate R _ { \mathrm { Virgo } } = 21 \mathrm { Mpc } given in Paper II .
Using a two-component mass-model we found a Virgo mass estimate M _ { \mathrm { Virgo } } = ( 1.5 – 2 ) \times M _ { \mathrm { virial } } , where M _ { \mathrm { virial } } = 9.375 \times 10 ^ { 14 } M _ { \sun } for R _ { \mathrm { Virgo } } = 21 \mathrm { Mpc } .
This estimate agrees with the conclusion in Paper I ( Teerikorpi et al . [ 1992 ] ) .

Our results indicate that the density distribution of luminous matter is shallower than that of the total gravitating matter when q _ { 0 } \leq 0.5 .
The preferred exponent in the density power law , \alpha \approx 2.5 , agrees with recent theoretical work on the universal density profile of dark matter clustering in an Einstein-deSitter universe ( Tittley & Couchman [ 1999 ] ) .