We investigate dark and visible matter distribution in the Coma cluster in the case of the Navarro-Frenk-White ( NFW ) profile .
A toy model where all galaxies in the cluster are concentrated inside a sphere of an effective radius R _ { eff } is considered .
It enables to obtain the mean velocity dispersion as a function of R _ { eff } .
We show that , within the observation accuracy of the NFW parameters , the calculated value of R _ { eff } can be rather close to the observable cutoff of the galaxy distribution .
Moreover , the comparison of our toy model with the observable data and simulations leads to the following preferable NFW parameters for the Coma cluster : R _ { 200 } \approx 1.77 h ^ { -1 } \mathrm { Mpc } = 2.61 \mathrm { Mpc } , c = 3 \div 4 and M _ { 200 } = 1.29 h ^ { -1 } \times 10 ^ { 15 } M _ { \odot } .
In the Coma cluster the most of galaxies are concentrated inside a sphere of the effective radius R _ { eff } \sim 3.7 Mpc and the line-of-sight velocity dispersion is 1004 \mathrm { km } \mathrm { s } ^ { -1 } .