1. Day 57 Outliers

2. Introduction
In some data, some points appear not to be inaccurately recorded due to their difference from others. These may be too large or too small as compared to other values. We would like to find out the importance of these values.

3. Vocabulary:
Outliers The are points that do not follow the general trend of other points in a given data.
This can be done in the notebooks or on vocabulary cards. Whatever system you use 

4. Outliers These are points that do not follow the trend of others in a given data. They may be too large or too small compared to other data points. These data points have an influence on mean, range, standard deviations but does not adversely affect mode and median. Thus, to get a true reflection of variability, that is, the standard deviation or the mean, they are sometimes left out. In cases where an outlier affects mean, standard deviation, it is referred to as an influence point.

5. An example of outliers is shown below Example 1

6. Example 2

7. Example 3

8. homework
A teacher would like to establish the mean age of students in grade 8. He samples out 12 students and records their age as shown below.
13, 13, 13.5, 13.5,14, 14, 14, 14.5,14.5,14.5, 15, 19.
a). Draw a scatter plot showing the data above.
b). Identify the outlier
c). Determine the mean with and without the outlier
d). Between the two means above, identify which one is the best for setting the mean age of a grade 8 student. Explain.

9. Answers homework
b). The outlier is 19 years c). Mean with the outlier is years Mean without the outlier is years

10. Answers homework
d). The best representative mean is the mean without outlier since the outlier does not represent the typical age of a grade 8 student.

11. THE END