The application of the I band Tully–Fisher relation towards determining the Hubble constant is reviewed , with particular attention to the impact of scatter and bias corrections in the relation .
A template relation is derived from galaxies in 24 clusters .
A subset of 14 clusters with cz \sim 4000 to 9000 km s ^ { -1 } is used as an inertial frame to define the velocity zero point of the relation .
Twelve galaxies with Cepheid distances are used to establish the absolute magnitude scale of the Tully–Fisher relation , and thus to determine a value of H _ { \circ } = 70 \pm 5 km s ^ { -1 } Mpc ^ { -1 } .
Estimates of the peculiar velocities of the Virgo and Fornax clusters are also given .
Assuming that the distance to Fornax is 18.2 Mpc ( N1365 ) , H _ { \circ } = 76 \pm 8 km s ^ { -1 } Mpc ^ { -1 } .
Assuming that Virgo lies at 17.4 Mpc ( M100 , N4496 , N4639 ) , H _ { \circ } = 67 \pm 8 km s ^ { -1 } Mpc ^ { -1 } .