σ2=E[(X−μ)2] ,其中 为标准差σ为标准差, μ 为X 的均值(期望) 进一步打开括号()里平方差,整理得到: σ2=E[(X−μ)2]=E(X2−2μX+μ2)=E(X2)−2μE(x)+μ2=E(X2)−μ2 至此我们得到了方差计算的另一个公式,这个公式需要注意的是:它提供了 E(X2) 与σ2 的关系。 当...
期望和方差是概率论和统计学中的基本概念。当我们谈论随机变量的特性时，这两个量尤其关键。首先，方差的计算公式是：方差 = [公式]，其中[公式]是期望值，也就是随机变量的平均值。这个公式揭示了随机变量与其均值的离散程度，平方差的引入使得方差更直观地表示数据的波动程度。对于两个独立随机变量X和...
5.3 EXPECTED VALUE AND VARIANCEChapter DISCRETE PROBABILITY
嗨,同学们,我是金程学姐~今天是我的核心100个考点中的第21个考点,也是数量的第6个考点,依然是属于概率论的知识点--- Expected Value and Variance 期望和方差 重点掌握单个随机变量X的期望和方差的计算,其实直接套公式就可以啦~ 本专辑更新时间:每晚17:00,和大家不见不散~ 如果觉得我们的内容对你有帮助,想...
1 数量分析 - Probability-multiplication rule, addition rule 1230 2021-03 2 数量分析 - Expected value and variance 1163 2021-03 3 数量分析 - Covariance 1218 2021-03 4 数量分析 - Correlation 1088 2021-03 5 数量分析 - Expected return and variance of portfolios ...
I told my brother Pan jinlian was dangerous 正在翻译,请等待... [translate] ato the expected value and the variance as, 到期待值和变化和, [translate] 英语翻译 日语翻译 韩语翻译 德语翻译 法语翻译 俄语翻译 阿拉伯语翻译 西班牙语翻译 葡萄牙语翻译 意大利语翻译 荷兰语翻译 瑞典语翻译 希腊语翻译 ...
functions of an RV, conditional probability mass function, conditional mean and variance. Probability mass function, families of discrete RVs, cumulative distribution function, expected value and variance, functions of an RV, conditional probability mass function, conditional mean and variance.[translate]...
Obtain the expected value and variance of X for the following probability distribution: View Solution Find the mean and variance of the frequency distribution given below View Solution Let X~B(n,p) then the mean or expected value of r. v. X is denoted by E(X) and is given by μ=...
Expected Value and Variance For a probability density functionf(x)which is nonzero on the interval[a,b],the expected value is given byE(X)=∫abxf(x)dx.The variance is given byVar(X)=∫abx2f(x)dx−μ2whereμ=E(...
This paper presents an index, referred to as the Expected Value – Variance – Skewness criterion, that incorporates skewness of net present value with its expected value and variance as a measure of investment worth under risk. The effectiveness of this criterion was compared to the expected ...