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Books? Books? Books?

Books? Books? Books?. Calculators out and ready to review!. Final Review Day 2. Create a Quiz!. Sample vs. Population Response/Explanatory Variable Positive/Negative Correlation Weak vs. Strong Correlation Coefficient ŷ = a + bx (positive vs. negative slope). Explanatory/Response.

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Books? Books? Books?

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  1. Books? Books? Books? Calculators out and ready to review!

  2. Final ReviewDay 2

  3. Create a Quiz! • Sample vs. Population • Response/Explanatory Variable • Positive/Negative Correlation • Weak vs. Strong Correlation Coefficient • ŷ = a + bx (positive vs. negative slope)

  4. Explanatory/Response • Suppose you were to collect data for a pair of given variables in order to make a scatterplot. For the variables cloudy days and rainy days, which is more naturally the response variable and which the explanatory variable? • Ex: Cloudy, R: Rainy

  5. Explanatory/Response • Suppose you were to collect data for a pair of given variables in order to make a scatterplot. For the variables time spent on homework and exam grades, which is more naturally the response variable and which the explanatory variable? • Ex: Time on HW, R: Grades

  6. Proportions • The partially completed conditional proportion table gives the relative frequencies of the data on age (in years) and gender for the residents of a retirement home. What percentage of the residents are males over 79?

  7. Proportions • The partially completed conditional proportion table gives the relative frequencies of the data on age (in years) and sex for the residents of a retirement home. What percentage of the residents are females in the age group 70 - 79?

  8. Complete the Table 25 15 20 11 9 40

  9. Correlation – positive, negative

  10. Correlation – positive, negative NONE

  11. Correlation – positive, negative

  12. Correlation – strongest?

  13. True or False? • The closer r is to 0, the weaker the linear association between the variables.

  14. True or False? • The value of the  correlation  is always  between 0 and 1.

  15. Find the equation of the line of best fit in your calculator

  16. True or False? • Association implies causation. Remember, eating ice cream didn’t CAUSE drownings…they just happened to occur at the same time of year (correlated).

  17. A survey of adults revealed a positive correlation between the height of the subject and their income in the previous year. • Explain how gender could be a potential lurking variable that could be responsible for the association.

  18. How many males were asked? 542

  19. Positive or Negative Slope? • ŷ = -209.9 + 25.5x Positive! (# in front of x)

  20. If r is 0.67… • Is this strong or weak? • What is the percent of variation? 44.89%

  21. ŷ = 1.27 + 0.475x • If y = 50.15 when x = 45.1, what is the residual? ^ y – y

  22. A drug company needs to test a new drug. Participants in an experiment are randomly given either the drug or a placebo. If the experiment conducted is double-blind, then… • The participants are blindfolded when they take the drug or placebo. • The participants do not know whether they are taking the drug or a placebo. • Neither the participants nor the drug company executives know which volunteers are taking the drug and which the placebo. • Neither the participants nor the evaluators know which volunteers are taking the drug and which the placebo.

  23. A survey is mailed to 1000 voters randomly selected from a county's registered voters asking "Do you support a constitutional amendment to ban abortion?" 235 are returned, and of these 180 respond "yes." • What’s the biggest source of bias? Nonresponse

  24. A magazine publisher mails a survey to every subscriber asking about the quality of its subscription service. From which of the following is this study most likely to suffer? • A)Undercoverage • B) Nonresponse bias • C) Sampling bias • D) Both nonresponse bias and undercoverage • E) Both undercoverage and sampling bias

  25. Our class is numbered from 1 to 30. Who are the first three numbers to be chosen according to this random number table? • 36574 47386 09127 55627 • 9, 12, 27

  26. Our class is numbered from 1 to 500. Who are the first three numbers to be chosen according to this random number table? • 36574 47382 09627 45697 • 365, 209, 456

  27. Retrospective or Prospective • A study found that nearly 90% of all child patients with asthma developed pneumonia in their teens. • A study found that nearly 90% of teens with pneumonia had asthma as a child. Prospective Retrospective

  28. What is the sampling frame? • I am going to do a survey of patients in a nearby hospital. • I want to ask O’Connor students their opinion on off campus lunches. • I want to ask Arizona residents their opinion on gun laws.

  29. What is a placebo?

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