The gravitational collapse of a gas cloud can be described by the Jeans Criterion for mass, radius and density of the gas cloud, which is (c stands for cloud):
$$M_J = (\frac{5kT}{G \mu m_H})^{3/2} (\frac{3}{4 \pi \rho_c}) ^{1/2} $$
$$R_J = (\frac{15kT}{4 \pi G \mu m_H \rho_c})^{1/2} $$
$$\rho_J = (\frac{3}{4 \pi M_c^2}) (\frac{5kT}{G \mu m_H}) ^{3}$$
I wanted to show that they are equivalent and simply used
$$\rho = \frac{m}{V} $$
on the criteria above an rearranged the equation.
However this doesn't work. What am I doing wrong?
Thank you for your help!