= Solution
Using the same <luminosity> estimate, the <distance modulus> is $12.5-(-22.49)=34.99$, implying $D\simeq99.4$ Mpc. Pure Hubble expansion at that distance predicts about $7450\,\mathrm{km\,s^{-1}}$. The measured <velocity> therefore implies
$$
\boxed{v_{\rm pec,los}\simeq6500-7450\simeq-950\,\mathrm{km\,s^{-1}}.}
$$
Its line-of-sight <peculiar velocity> is toward us, of the order expected for orbital motions in a rich <galaxy> cluster. A <galaxy> falling toward a cluster centre from its far side could have this sign. Its actual front/back location or three-dimensional orbit is not determined without the cluster's mean <velocity>, distance and projected <position>. Tully-Fisher scatter and the assumption of identical <luminosities> also limit that inference.
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