How come when i wake up at night a black figure is standing over me

Ascientist performs an experiment where she measures the mass of a piece of metal, pours acid onto the metal, washes the metal, and then re-measures the mass of the metal. the scientist repeats the experiment several times, each time increasing the amount of acid used. the dependent variable in the experiment is the: initial mass of the metal final mass of the metal amount of acid used washing the metal

For most of the twentieth century, percentage of men had a college degree compared to women. however, if we focus on the data for americans born in or later, a higher percentage of women hold college degrees.

Can someone me out with this , i'm putting 30 points on it