standard_description: Recognize that a measure of center for a numerical data set summarizes all of its values with a single number, while a measure of variation describes how its values vary with a single number.
problem_activity: You are shoveling snow from the sidewalks around your neighborhood after a big snowstorm. You work at a steady rate, shoveling 10 feet of sidewalk in 40 minutes.
a.   At this rate, how long will it take you to shovel 75 feet of sidewalk?
b.   At this rate, how many feet of sidewalk will you have shoveled after 2 hours?


aligns: no