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(X≤x )
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
X∼U(a,b)
The mean is μ=a+b2
The standard deviation is σ=√(b−a)212
Probability density function: f(x)=1b−a for a≤X≤b
Area to the Left of x:P(X<x)=(x−a)(1b−a)
Area to the Right of x:P(X>x)=(b−x)(1b−a)
Area Between c and d : P(c<x<d)=( base)(height) =(d−c)(1b−a)
- pdf: f(x)=1b−a for a≤x≤b
- cdf: P(X≤x)=x−ab−a
- mean μ=a+b2
- standard deviation σ=√(b−a)212
- P(c<X<d)=(d−c)(1b−a)
5.4 The Exponential Distribution
- pdf: f(x)=me(−mx) where x≥0 and m>0
- cdf: P(X≤x)=1−e(−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)=μxe−μx! with mean and variance of μ