Question

A star is estimated to have a mass of 4.4x1026lbs. It has a diameter of 8.69x105 mi. Calculate the density in g/cm3.

Answer 1

I assume this star is a sphere.

Change the 4.4E26 lb to grams. You know there are 454 g/lb.
Change 8.69E5 miles to cm. You know there are 5,280 ft/mi and 12 in/ft and 2.54 cm/in. Radius is 1/2 diameter Volume of a sphere is 4/3*pi*r^3
Then density = g/cc
Post your work if you get stuck.