Back to Define appropriate quantities — Problem 2 · Task Set 5

Exercises: Define Appropriate Quantities for the Purpose of Descriptive Modeling

Work through each section in order. For explanation problems, write in complete sentences. There is often more than one defensible answer — focus on justifying your choice clearly.

Grade 9·22 problems·~45 min·Common Core Math - HS Number and Quantity·standard·hsn-q-a-2

Work through problems with immediate feedback

Fluency Practice

U.S. highway fatalities: in 2019, total fatalities were about 36,000 and total vehicle-miles traveled were about 3.3 trillion. In 2000, total fatalities were about 41,000 and vehicle-miles were about 2.75 trillion. Which statement correctly compares safety across the two years?

Highways became safer because total fatalities fell from 41,000 to 36,000.

Highways became less safe because more miles were driven in 2019.

Highways became safer: fatalities per 100 million vehicle-miles fell from 1.49 to 1.09, controlling for total driving volume.

We cannot determine safety trends from this data alone.