The pressure inside a balloon is 4.30 atm and its volume is 40.0 mL. If the pressure increases to 4.80 atm, what is its resulting volume in mL?

You know how the first one if filled up like the objects do the same but with the other categories

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .