I'm really stuck. I need to figure out the mass/light ratio of a galaxy in solar units. I know its mass is 5.7 x 1010 solar masses. I know its absolute magnitude (-17.3) and distance (29 Mpc). I'm feeling dumb here because I think this ought to be clear to me, but I'm getting hung up at the magnitude - luminosity - light part.
Here's what I think: mass/light = 100.4*(Magnitude galaxy-magnitude Sun) x (mass galaxy/mass Sun)
I get a mass to light ratio of around 90. Am I doing this right?