Back to Distinguish surveys, experiments, and observational studies — Problem 4 · Task Set 14

Exercises: Distinguish Surveys, Experiments, and Observational Studies

Work through each section in order. For classification problems, decide whether a study is a sample survey, an observational study, or a randomized experiment, and use two separate questions: "Was there random SELECTION?" (which governs whether results generalize to a population) and "Was there random ASSIGNMENT?" (which governs whether a difference can be read as causation). For explanation problems, write in complete sentences.

Grade 10·21 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-ic-b-3

Work through problems with immediate feedback

Fluency Practice

Classify each study and identify the role of randomization.

A study randomly draws a sample of adults from a city and surveys their coffee habits and sleep. It does NOT assign anyone to drink coffee. Which randomization did this study use, and what does it license?

Random selection only; results generalize to the city, but the study shows association, not causation.

Random assignment only; the study can establish that coffee affects sleep.

Both randomizations; the study generalizes AND establishes causation.

Neither randomization; the study can conclude nothing.