hydrostatic equilibrium. The [ <span style="font-variant:small-caps;">HI</span> ]{}layer flares out at large radii, as there is less matter gravitationally binding it to the central plane. Because of this, flaring provides a sensitive tracer of the vertical potential as a function of radius in the disc. By combining this with the horizontal potential as gained from the rotation curve, and estimates for the gas and stellar mass distributions, one can fit the potential well created by the dark matter halo. This method was first applied to the Galaxy by @Celnik1979A and by @vdk81c on edge-on galaxy NGC891. In the latter it was found that the halo was spherical rather than flattened as the stellar disc. NGC4244 was analysed by @Olling1995A, who found a highly flattened halo of $q=0.2^{+0.3}_{-0.1}$. @OBrien2010D also set out to measure the velocity dispersion as function of radius. Using that approach to measure the halo shape of [UGC7321]{}, they found a spherical halo ($q = 1.0 \pm 0.1$).

This paper is the fifth in a series. We will refer to earlier papers of the series simply as Papers I through IV. In this paper V, we will perform a similar analysis, using the measured parameters for the [ <span 