## Distribution

- The important distributions are –
- Binomial Distribution
- Poisson Distribution
- Normal Distribution

## Binomial & Poisson Distribution

- A lot contains large number of items with a proportion of defective ‘p’ then random sample of ‘n’ items from a lot contain 0,1,2,…p…,n defectives and the probability of getting the events approximated by these distribution.
- These are discrete distributions
- Binomial distribution contains finite number of values
- Poisson distribution contains infinite number of values
- Examples : P-Chart, nP-Chart, C-Chart, U-Chart Attribute Control Charts

## Normal Distribution

- This is a continuous distribution, contains rational or irrational values
- This distribution is categorized by two parameters
- Average (μ)
- Standard Deviation (σ)

y = 1/σ*2 π ex {-(x-μ)2/2 σ2}

Examples : Average-Range Control Chart, Sigma-Range Control Chart, Moving Range Control Chart

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