Let the sum of the 3 consecutive terms in AP be 180 then middle of those 3 terms would be

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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 .

Ithink the answer is d

Answer(true);