HW1

1.1

• 1. Statistics is the science of collecting, organizing, summarizing, and analysing information to draw conclsions or answer questions. In addition, statistics is about providing a measure of confidence in any 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. The population is all of the teenagers aged 13-17. The sample is the group of 1028 teenagers contacted by the organisation.
• 40. The population is all of the Coca-Cola bottles filled on October 15. The sample is the 50 bottles selected for quality control.
• 41. The population is all of the soybean crop. The sample is the 100 plants the farmer selected to weigh.
• 42. The 50,000 households in the census report are a sample of the entire US population.

1.2

• 13. This is an observational study because the researchers only observed what peoples prefrences were and they didn’t manipulate any of the variables.
• 14. This is an observation because no variable was manipulated. The people in the study were only asked to taste test drinks and see which one they preffered.
• 15. This is an experiment because the explanatory variable was manipulated to see the effects on the response variables.
• 16. This is an observation because no attempt was made to manipulate any variables. The 250 large-mouth bass were only caught to determine if they were carrying parasites or not.
• 17. 1. This is a cohort study because the group of people were observed over a period of time. b) The response variable is whether each individual has a heart disease or not. The explanatory variable is whether or not each individual is happy. c) This sentence means that there may be confounding because of lurking variables. Perhaps happy people may excercise more thus affecting the occurence of heart disease.
• 18. 1. This is a cross-sectional study because it just asks for the participants coffee drinking habits and whether the women have had nonmelanoma cancer which is easy and quick information to gather. b) The response variable is the occurence is skin cancer. The explanatory variable is the daily consumption of coffee. c) It was important to adjust for these variables in order to acknowledge that there were confounding variables that may have influenced the outcome of the data gathered.