A boy inflated a bunch of balloons while he was outside with an ambient temperature of 26oC. He then took the balloons inside his air-conditioned house where the temperature was 20oC. What do you think happened to the balloons?

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 .