Question

You are interested in the effect of the (tobacco) smoking behavior of the mother orn birth weight. You have data about 1,338 births in the US that contain the infant's birth weight in ounces (bwght) and the average number of cigarettes the mother smoke during pregnancy (cigs) 1. What is the dependent and what is the independent variable? 2. You run a linear regression, and you got from the output that bwght 117.55-0.495cigs What is the predicted birth weight of the mother did not smoke during pregnancy? What is the predicted birth weight if the mother smoke 20 cigarettes (-1 pack) during pregnancy? Comment on the difference. (Which one is smaller, big difference, small difference in your opinion... .etc) 3. Does this simple regression necessarily capture the causal relationship between the child's birth weight and the mother's smoking behavior? Explain and interpret the slope coefficient (depending on your answer

please answer completely, and show all work

Answer 1

Independent variable: An independent variable is a variable that represent a quantity that is being manipulated in an experiment x is often the variable lued to represent the independent variable in an equation Dependent variables: A dependent variable represents a quantity whose value depends on how the independent variable is manipulated . Y is often the variable used to represent the dependent variable in an equation 2) Where bwgt = 117 . 55 - 0 . 495 [20] = 107.65 Mother who smoke cigarette during pregnancy have, on average, lower birth weight childrens 3) rightarrow smoking precedes the birth of the child and smoking can be consider casual rightarrow The other factors which can effect the birth weight of children such as health of the mother and other environmental condition rightarrow therefore multiple regression of birth weight on there factor we are likely to see that smoking should be still maintain