Need help with Chemistry, 10 pts

How would I find the theoretical density and percent errors of the unknown liquid and unknown solid, using this information?

-Unknown liquid
Graduated cylinder mass in grams: 44.52
Graduated cylinder and unknown liquid mass in grams: 58.52
Mass: 14
Volume in mL: 17.8
Density in g/ml: .8
percent error: ?

I don't necessarily need the answer, I just need to know how to do it. Thanks!

you are fine so far but without the theoretical density, you cannot determine % error. and, you can't use the theoretical density if you either don't know what the substance is or if someone tells you the density.

if you get the theoretical density, % error = experimental value / theoretical value x 100%