Day 06: Statistics for Business Applications

Last Time:
- Review of measures of spread
  - Especially the standard deviation (square root of the variance)
  - Empirical rule (for bell-shaped distributions): 68/95/99
  - Chebysheff's Theorem: the (conservative) 0/75/89 rule
- Started chapter 8, section 3: the normal distribution
Today:
- Return homeworks:
  - Chapter 4, section 1-2
  - I need to see histograms! You can't talk about an invisible histogram and expect me to understand....
  - Use descriptive titles on histograms (and on your work in general).
- Do you have any questions about the homework associated with 4.3? (Due Tuesday - no homework due today)
- Chapter 8: The normal distribution and probabilities
  - The empirical rule - the 68/95/99 rule - comes from the normal curve
  - Probabilities and the area under the curve
    - What are probabilities? (Certainly you've rolled dice....)
    - A calculator for normal probabilities
    - Calculating a Z-score (standardizing a normal curve. All normals are really the same - just shifted and stretched!)
    - Using the Z table of normal probabilities (p. 235)
    - Some examples
Next time:
- 4.3 problems are due
- Start chapter 9 (sampling distributions)

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