The main target this paper is to check a theory about dark matter nature, which was published by the author in previous papers. It was postulated and supported, with several experimental evidences, that dark matter density is a function which depend on E, gravitational field, according to an Universal law for big galaxies. Current paper studies a similar law for NGC 3198, which is an intermediate galaxy belong to Ursa Major cluster, 14 Mpc away. In this work has been fitted a new function for DM density as power of E. Reader could think, why disturb me with a new DM density profile, called Bernoulli profile in this paper, whose values have relative differences with NFW ones below 5%? The reason is clear. This DM profile has been got starting from hypothesis that DM is generated by the own gravitational field. Therefore if DM Bernoulli profile fits perfectly to observational data of DM and NFW profile as well then it is possible conclude that observational data supports author´s hypothesis about DM nature. To find reasons that author has to do so daring statement, reader can consult [1] Abarca,M.2014. Dark matter model by quantum vacuum and [2] Abarca,M.2015. Dark matter density function depending on gravitational field as Universal law Briefly will be explained method followed to develop this paper. Firstly are presented rotation curve and table with data about DM density inside halo of NGC 3198 galaxy. These data come from [3] E.V. Karukes, 2015. In fourth epigraph, starting from spin speed from Karukes data, it is right to calculate gravitational field E, through Virial theorem. So in this epigraph has been tabulate gravitational field and density of dark matter inside a wide region of halo, from 18 kpc to 46 Kpc. In fifth epigraph has been fitted data of DM density as power of gravitational field, E, with a correlation coefficient bigger than 0,99. Particularly formula found is Density Dark matter = A • E^B Where A= 4,04598703 •10^-5 and B= 1,70654481 In sixth and seventh epigraph it has been compared DM density data, DM density as power of E, NFW & Burket profiles. Tables and plots show clearly that DM density power of E adjusts better than the other ones. In eight epigraph it is considered derivative of gravitational in halo region where density of baryonic matter is negligible. As consequence M´(r ) = 4 pi r^2 • Density Dark matter (r) and considering that Dark matter = A • E^B then M´(r ) = 4 pi r^2 • A • E^B. If M´(r) is replaced on derivative of E (r) then it is got a Bernoulli differential equation whose solution is a new DM density profile. To integrate differential equation has been taken four different values for gravitational field at four different radius to check accuracy of integration parameter. In nineth epigraph Bernoulli, NFW and Burket DM density profiles have been compared to Karukes data of DM density. Results show clearly that Bernoulli profile fits better than the other ones. Paper finish concluding that results supports clearly hypothesis about DM nature defended by the autor.