If a gas is known to have a pressure of 200 kPa after it has been heated to 65°C, what was the beginning Celsius temperature of the gas if its pressure
was originally 750 mm Hg?

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 .