chem 221/222 -Midterm Exam: Part 1 (Theory)

The Baltimore data set has 506 observations, we create a model “medv ~ rm + lstat + ptratio + tax + nox + indus”. The results of the summary: Q1. What is the adjusted R-squared? For questions 2-4 we are going to use the abalone dataset. All questions are independent to each other. You do not have to use code for the following questions. We will build a linear regression model using the Length (in mm) as the response variable and the Sex (Infant, Male, Female) and Height (in mm) as predicting variables. Using Sex = Female as the base case, we create 2 indicator (or dummy) variables SexInfant and SexMale for Sex = Infant and Sex = Male, re spectively. Then, we fit the model and we obtain the output provided below. Use this output to answer questions 2 & 3. For abalone with the same height, those that are male are expected to have greater length than female ones.