HW1

1.1

• 1. Statistics is collecting, organizing, summarizing, and analyzing information to form answers or conclusions.
• 3. Individual
• 5. Statistic, parameter
• 7. parameter
• 9. statistic
• 11. parameter
• 13. statistic
• 15. qualitative
• 17. quantitative
• 19. quantitative
• 21. qualitative
• 23. discrete
• 25. continuous
• 27. continuous
• 29. discrete
• 39. population: teenagers who are 13-17 years old. Sample: 1028 teenagers
• 40. Population: bottles that were filled on October 15. Sample: 50 bottles
• 41. Population: randomly sampled plants. Sample: 100 plants
• 42. Popuation: households within the U.S.. Sample: 50,000 households.

1.2

• 13. Observational
• 14. Experiment
• 15. Experiment
• 16. Observational
• 17. 1. Cohort study because it identifies a group of individuals to participate in the study, and the cohort is observed over a long period of time, which in this case is 10 years. Also because during this 10 year period, some individuals may be exposed to certain factors and some will not that could influence the results of the study.

2. Response variable: heart disease Explanatory variable: level of happiness
3. the research team reported that genetics is a lurking variable becuase it could have affected the value of the response variable in the study

• 18. 1. cross-sectional study because the researchers studied one group of women over a short period of time, and the information was collected at a specific point in time with no matching or follow-ups.

2. Response variable: whether the women has nonmelanoma skin cancer or not. Explanatory variable: consumption of coffee
3. Because of cofounding variables! When two or more explanatory variables are not accounted for or separated in the study, it could affect the value of the response variable.