1. One Quantitative Variable: Shape and Center
Section 2.2
One Quantitative Variable: Shape and Center

2. Review
Given the two-way table from last class, approximately what percentage of patients who survived received Paricalcitol?
58%
53%
50%
29%
Survived
Died
Total
Calcitriol
17,252
16,248
33,500
Paricalcitol
19,665
13,835
36,917
30,083
67,000
19665/36917

3. Histogram vs Bar Chart This is a Histogram Bar chart Other
I have no idea

4. Histogram vs Bar Chart This is a Histogram Bar chart Other
I have no idea

5. New Homes Prices of new homes are most likely symmetric
skewed to the left
skewed to the right

6. Skewness and Center
A distribution is left-skewed. Which measure of center would you expect to be higher?
Mean
Median
The mean will be pulled down towards the skewness (towards the long tail).

7. The distribution of 2010-11 NHL Salaries is shown, in millions of dollars. The distribution is:
A. Symmetric B. Skewed right C. Skewed left

8. The distribution of 2010-11 NHL Salaries is shown.
Which is larger, the mean or the median?
A. The mean B. The median

9. The median is approximately (in millions of dollars)
A B C D E. 5.0

10. The mean is approximately (in millions of dollars)
A B C D E. 5.0

11. Example: 2010-11 NHL Salaries
Mean is “pulled” in the direction of skewness
x=$2,210,000