Determine Whether Each Situation Describes a Survey, an Observational Study, Or an Experiment

Algebra2 Name

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Determine whether each situation describes a survey, an observational study, or an experiment. Explain your reasoning.

1. A grocery store conducts an online study in which customers are randomly selected and asked to provide feedback on their shopping experience.

2. A research group randomly selects 80 college students, half of whom took a physics course in high school, and compare their grades in a college physics course.

3. A research group randomly chooses 100 people to participate in a study to determine whether eating blueberries reduces the risk of heart disease for adults. Half of them are instructed to eat blueberries at least once a week and the other half are asked to avoid eating blueberries.

4. A fashion magazine plans to poll 100 randomly selected people in the U.S. to determine whether they would be more likely to buy a subscription if given a free issue.

5. Chee wants to examine the eating habits of 100 random students at lunch to determine how many students eat in the cafeteria.

6. To test the effect on the strength of metal car parts, an engineer assigns 25 parts to be made of a new titanium alloy and assigns another 25 to be made of a different alloy.

7. If an economics professor at a university wants to look for patterns in federal government policies and their impact on the economy, should they conduct a sample survey, an observational study, or an experiment?Why not conduct the others?

8. If a health researcher wants to look for possible relationships between the use of a certain medication and a certain medical complication, should they conduct a sample survey, an observational study, or an experiment?Why not conduct the others?

9. If a market researcher wants to estimate the percent of people who have seen a movie in theaters in the past 2 weeks, should they conduct a sample survey, an observational study, or an experiment? Why not conduct the others?

10. If a food scientist wants to determine whether the type of sugar used when making bread makes a difference in how long the bread stays fresh, should they conduct a sample survey, an observational study, or an experiment? Why not conduct the others?

11. What is the difference between an observational study and a sample survey?

12. What is the difference between an observational study and an experiment?

13. What is the difference between an experiment and a sample survey?

14. Why do we use random samples in sample surveys?

15. Why do we use random samples in observational studies?

16. Why do we use random assignment in experiments?