A Spiral Galaxy of type Sc has a maximum rotational velocity of 138 km/s at a radius of 15 kpc. Estimate the Mass-to-Light ratio in the B-band for this galaxy. That is, calculate the ratio of ( ) where M is the mass and is the luminosity in the B-band. Give your answer in units of Solar masses / Solar luminosity, where the mass-to-light ratio of the Sun would be , so you would enter 1.0 for your answer if you were dealing with the Sun. Give your answer to a 3% accuracy. Hints: For this problem you will have to calculate both the Luminosity in the B-band (like the question above) and Mass (like the previous problem). Then you take the ratio