See lesson posted at https://melindahiggins2000.github.io/N736Fall2017_lesson06/lesson06_dataWranglingPt2.html
Github repo for Lesson 06 at https://github.com/melindahiggins2000/N736Fall2017_lesson06
Copyright © Melinda Higgins, Ph.D.. All contents under (CC) BY-NC-SA license, unless otherwise noted.