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5.6: Formula Review

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5.2 Properties of Continuous Probability Density Functions

Probability density function (pdf) f(x) :

  • f(x)0
  • The total area under the curve f(x) is one.

Cumulative distribution function (cdf): P(Xx )

5.3 The Uniform Distribution

X= a real number between a and b (in some instances, X can take on the values a and b ). a= smallest X;b= largest X
XU(a,b)

The mean is μ=a+b2

The standard deviation is σ=(ba)212

Probability density function: f(x)=1ba for aXb

Area to the Left of x:P(X<x)=(xa)(1ba)

Area to the Right of x:P(X>x)=(bx)(1ba)

Area Between c and d : P(c<x<d)=( base)(height) =(dc)(1ba)

  • pdf: f(x)=1ba for axb
  • cdf: P(Xx)=xaba
  • mean μ=a+b2
  • standard deviation σ=(ba)212
  • P(c<X<d)=(dc)(1ba)

5.4 The Exponential Distribution

  • pdf: f(x)=me(mx) where x0 and m>0
  • cdf: P(Xx)=1e(mx)
  • mean μ=1m
  • standard deviation σ=μ
  • Additionally
    • P(X>x)=e(mx)
    • P(a<X<b)=e(ma)e(mb)
  • Poisson probability: P(X=x)=μxeμx! with mean and variance of μ

5.6: Formula Review is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

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