Both readers realized that the decay factor on the exponential average was one minus the smoothing factor, and substituting these into the equation would reduce it further. My hat is off to Carey Barnett and Paul H. Lasky.
Superior methods are more likely to produce truthful, credible and precise findings.
The difference between an excellent analysis and a faulty one can sometime have momentous consequences. The book is the third in a series of self-published masterworks on the art and science of making data understandable using visualizations. Tufte's first, The Visual Display of Quantitative Information , was published in 1983 and still is produced. I picked up a copy in 1985, and it remains the bible of making good charts. Envisioning Information is the second in the series.