# OpenDocProject:Stats400/2010/08/24

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## Chapter 1 Notes

Statistics in Industry, three points:

1. Variation exists in all processes
2. Understanding and reducing undesirable variation is a key to success
3. All work occurs in a system of interconnected processes

Statisticians try find patterns, in face of variations, we look for best descriptions of patterns. Acknowledge errors will be made and that stats can bound errors

Stats is the study part of "plan-do-study-act" cycle.
Random Experiments = outcome cannot be known Outcome Space = collection of all outcomes Sample Space = "" or S Random Variables = measurements on outcomes associated with random experiments "'statistical inference"' = a conjecture Distribution of the random variable (also called) population : number of times a random exp ends in a respective result.

mode = mode measurement that occurs most often Probably Mass Function = f (x)

mode of a distribution means the the value that has a greatest probability (same as above, just rephrased)

"Simpson's Paradox" = the number of times instances in a single observation does not say anything about the whole of observations -- for instance, player A can have a better Batting Average than player B every year of their career, but player b might have a higher career Batting Average.