1. Section 2.4 notes continued
Statistics
Section 2.4 notes continued

2. Finding the mean from a frequency table – Because the actual data is lost in a freq table, the best we can do is to estimate the mean.
For each class, find the class midpoint and multiply that number by the corresponding frequency. Add those products together and then divide by the total frequency.

4. Skewness
Figure
2-13 (b)
Mode = Mean = Median
SYMMETRIC

5. Skewness SYMMETRIC SKEWED LEFT (negatively) Figure 2-13 (b) Figure
Mode = Mean = Median
SYMMETRIC
Mean
Mode
Median
Figure
2-13 (a)
SKEWED LEFT
(negatively)

6. Skewness SYMMETRIC SKEWED LEFT SKEWED RIGHT (negatively) (positively)
Figure
2-13 (b)
Mode = Mean = Median
SYMMETRIC
Mean
Mode
Mode
Mean
Median
Median
Figure
2-13 (a)
SKEWED LEFT
(negatively)
SKEWED RIGHT
(positively)
Figure
2-13 (c)