What is the most believable part of the big bang theory?

What is the independent variable in this investigation? mass volume sample number substance density

Can someone me with 3 and 4 plz. this is for masteries test.

To prevent the presence of air, noble gases are placed over highly reactive chemicals to act as inert "blanketing" gases. a chemical engineer places a mixture of noble gases consisting of 4.37 g of he, 13.36 g of ne, and 36.65 g of kr in a piston-cylinder assembly at stp. calculate the partial pressure in torr of kr.