Today:
- Return Quiz 3
- Comments
- Lots of folks confusing median with mode
- Lots of folks getting the relative positions of mean and mode
confused on a skew distribution
- The mean is the balance point
- The median is the place where 50% of the data is to the left, 50%
of the data is to the right.
- Statistics:
- sample mean xbar = 8.45
- sample median = 8
- sample standard deviation s = 1.44
- Quiz 4 -- next time, on variation
- Chapter 4, sections 1-4: the normal distribution
- Figure 4.4, p. 105 and the Empirical Rule
- Percentages in categories
- Percentages over categories
- Practical Example:
Problems A, B of Chapter 4
Example
- What do we do with Problem C?
- Example: #3, p. 108
- Z-statistic
- The definition:
- "Z table" (p. 111)
- Deducing/refining the empirical rule
- Using the Z table to do problems:
- Percentage/fraction/probability (p. 123)
- All probabilities are between 0 and 1
- A probability of 0 means that an outcome of interest will
never occur.
- A probability of 1 means that an outcome of interest is
certain to occur.
- #8, p. 126
- Using the Z-table backwards:
Website maintained by Andy Long.
Comments appreciated.