The mathematical purpose of this lesson is for students to practice calculating and applying the standard deviation in real-world contexts. Previously, students learned how to calculate the standard deviation and discovered its value in decision-making. In the associated Algebra 1 lesson, students apply their understanding of standard deviation to real-world contexts. The third activity in this lesson allows students to characterize the best route as one that is not only faster than the other, but more or less consistent, predictable, and efficient than the other. Students reason abstractly and quantitatively (MP2) when they use appropriate statistics for a situation to decide a better option.