HW1

1.1

• 1. Statistics is the science of collecting, organizing, summarizing, and analyzing information in order to draw conclusions and answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.
• 3. Individual
• 5. (A). Statistic (B.) Parameter
• 7. 18% is a parameter because it is describing a population
• 9. 32% is a statistic because it is describing a sample
• 11. 0.366 is a parameter because it is describing a population
• 13. 23% is a statistic because it describes a sample
• 15. Qualitative
• 17. Quanitative
• 19. Quanitative
• 21. Qualitative
• 23. Discrete
• 25. Continuous
• 27. Continuous
• 29. Discrete
• 39. The population consists of the teenagers, 13-17 years old, who live in the US. The sample consists of the 1,028 teenagers 13-17 years old who are contacted by the Gallup Organization.
• 40. The population consists of all the Coca-Cola. The sample consists of the 50 bottles of Coca Cola that were filled on October 15th.
• 41. The population consists of all the soybean plants in the farmers’ crop. The sample consists of the 100 soybean plants that were selected by the farmer.
• 42. The population consists of all households within the U.S. The sample conists of the 50,000 households that were surveyed.

1.2

• 13. This is considered an observational study because the survey only observed preferences for Coke or Pepsi. Thus, there was no attempt made to manipulate or influence the variable of interest.
• 14. This is considered an observational study because the survey only observed the preferences of which drink one preferred. Thus, there was no attempt made to maniulate or influence the variable of interest.
• 15. This is considered an experiement because the explanatory variable, carpal tunnel treatment regimen, was intentionally manipulated in order to boserve potential effects of the response variable, which was the level of pain.
• 16. This is considered an observational study because the survey only determined whether or not the large-mouth bass were carrying parasites. Thus, there was no attempt made to maniulate or influence the variable of interest.
• 17. 1. This is a cohort study because the researchers observed a group of people over a period of time
  2. The response variable is whether the individual has heart disease or not. The explanatory variable is whether the individual is happy or not.
  3. There could possibly be confounding due to lurking variables. People that are happier may be more inclined to excercise, versus those who are less happy, for example, which could affect whether they have a heart disease or not.
• 18. 1. This is a cross-sectional study because researchers were only looking at one group of women over a short period of time.
  2. The response variable is whether or not the women had nonmelanoma skin cancer. The explanatory variable was whether or not the women were drinking coffee.
  3. It is important to adjust for these variables because their population could have been extremely similar, which would mean they all lead very similiar lifestyles. However, the more randomized the population–the more accurate one’s results will be.