Section Causation AP Statistics ww.toddfadoir.com/apstats

AP Statistics, Section 4.2, Part 22 The Question of Causation More than showing that “variable x is associated to variable y” most people are interested in the question “does variable x cause variable y” It is much more difficult to show causation than it is to show association.

AP Statistics, Section 4.2, Part 23 xy Strong Association Causation

AP Statistics, Section 4.2, Part 24 True Causation x: Mother’s body mass index y: Daughter’s body mass index Body type is in part determined by heredity. Daughters inherit half their genes from their mothers. There is causation even though the mothers’ BMI explain 25.6% of the variation among the daughters’ BMI. (Page 233)

AP Statistics, Section 4.2, Part 25 True Causation x: amounts of artificial sweetener saccharin in a rat’s diet y: count of tumors in the rats’ bladders By putting rats into groups and feeding only one group saccharin, we can isolate the change the effect of the saccharin. Note: a similar effect was not found in humans. (Page 233)

AP Statistics, Section 4.2, Part 26 xy Strong Association Causation z

AP Statistics, Section 4.2, Part 27 Not Causation, Common Response x: a high school senior SAT score y: the student’s first-year college grades Even though there is a strong association between both variables, they are most likely responding to the common variables ability and knowledge. (Page 233)

AP Statistics, Section 4.2, Part 28 xy Strong Association ? z1z1 z2z2 z3z3

AP Statistics, Section 4.2, Part 29 Confounding Variables Two variables are confounded when their effects on a response variable cannot be distinguished from each other.

AP Statistics, Section 4.2, Part 210 Not Causation, Confounding Variables x: whether a person regularly attends religious services y: how long a person lives People who attend religious service do live longer, studies also show that they tend to take better care of themselves. They are less likely to smoke, more likely to exercise and less likely to be overweight (Page 234)

AP Statistics, Section 4.2, Part 211 Assignment Exercises: , 4.41, 4.42, 4.43, 4.45, 4.47 Learner.org, Against All Odds Video on Causation