第2章概率分布 Normal Distrib .Other Continuous Distributions
第2章 概率分布 •Normal Distribution •Other Continuous Distributions
本章概要 The Normal distribution The Standard Normal distribution . Assessing the Normality Assumption The Exponential Distribution .Sampling Distribution of the Mean Sampling Distribution of the Proportion Sampling from Finite populations
本章概要 •The Normal Distribution •The Standard Normal Distribution •Assessing the Normality Assumption •The Exponential Distribution •Sampling Distribution of the Mean •Sampling Distribution of the Proportion •Sampling From Finite Populations
Continuous Probability Distributions 连续的概率分布 Continuous Random variable Values from Interval of Numbers Continuous Probability Distribution: Distribution of a Continuous Variable .Most Important Continuous Probability Distribution the Normal Distribution
Continuous Probability Distributions 连续的概率分布 •Continuous Random Variable: Values from Interval of Numbers Continuous Probability Distribution: Distribution of a Continuous Variable •Most Important Continuous Probability Distribution: the Normal Distribution
The normal distribution 正态分布 Bell Shaped Symmetrical f(X) Mean Median and Mode are Equal X Middle Spread? Mean Equals1.33σ Median Random variable has Mode Infinite Range
The Normal Distribution 正态分布 • Bell Shaped • Symmetrical • Mean, Median and Mode are Equal • Middle Spread? Equals 1.33 • Random Variable has Infinite Range Mean Median Mode X f(X)
概率密度函数 (Probability Density Function, p.d.f.) 1(-1/2)(x-po 2no fX)- frequency of random variable X 3.14159;e=2.71828 population standard deviation value of random variable (-o0< X<oo) population mean 总体均数)
概率密度函数 (Probability Density Function, p.d.f. ) f(X) = frequency of random variable X = 3.14159; e = 2.71828 = population standard deviation X = value of random variable (- < X < ) = population mean (总体均数) f(X) = 1 e (-1/2)((X- )) 2 2