Supporting Statistical Analysis for Research

## 3.1 Preparatory exercises

The skills in these exercises are used in the exercises at the end of the discourses of this chapter. Take a moment and complete these to confirm that you are prepared for this chapter. If these exercises are difficult, review the prior chapter.

1. Import the MplsStops.csv data set.

Hint: It may take a large number of rows to determine the correct type for some variables.

2. Are there any rows that need to be ignored in the MplsStops data set?

3. Are there any special symbols that need to be set to missing in the MplsStops data set? If so, change the special symbols to the missing indicator.

4. Sort the data frame by policePrecinct. Hint, This requires searching outside of the material that has been covered.