A tower built of Iron is 500 meter tall. What is the change in height (m) if it is exposed to 25 0 Celsius during summer and at 1.00 Celsius during winter. α iron = 1.2 x 10-5/ Celsius

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 .