An example of how to draw a trend line with it’s 95%-CI (Confidence Interval of 95%).
Usages :
- Drag & Drop each point to see the impact on the trend line and 95%-CI
- Drag & Drop the timeline to see that this has no impact nor on the trend, nor on the 95%-CI
- increase or decrease the dispersion of the time serie to see that this impacts the 95%-CI, but not the trend
- points outside a confidence interval may be considered outliers; they are important points, and finding the root/business cause of such points may be crucial (even if they may be the consequence of evidence (eg. increase of sell due to a discount)).
Notes:
- trend line computed using least square method
- 95%-CI computed using +/- 1,96*standard deviation; other intervals (e.g. 99%-CI) can be used
Acknowledgments: