Common Probability Distributions

Common Probability Distributions

Continuous Uniform Distribution:

图示

Binomial distribution

图示

● E(X)=np

● D(X)=np(1-p)

Poisson Distribution

图示

● E(X)=λ

● D(X)=λ

Normal Distribution:

● Completely described by mean and variance (μ,σ2).

● It is symmetric with skewness measure of 0,i.e.,mean=mode=median.(https://www.daowen.com)

● Kurtosis=3.

● Linear combinations of normal random variables are normally distributed.

● Standardized Normal Distribution

图示

● Confidence Interval

68% of observations fall within±1σ.

90% of observations fall within±1.65σ.

95% of observations fall within±1.96σ.

99% of observations fall within±2.58σ.

Student's t-distribution:

● Student's t-distribution:is symmetric;fatter tails;

● Degrees of freedom=(n-1).