开发者:上海品职教育科技有限公司 隐私政策详情

应用版本:4.2.11(IOS)|3.2.5(安卓)APP下载

Drink H · 2020年01月15日

问一道题:NO.PZ2020010302000009

问题如下:

Consider the following data on a discrete random variable X:

a. Calculate the mean and variance of X.

b. Standardize X and check that the mean and variance of X are 0 and 1 respectively.

c. Calculate the skew and kurtosis of X.

选项:

解释:

a. The mean is -0.803 and the variance is 6.762.

b.


c.


Hence, the skew of X is -0.581 and the kurtosis of X is 2.773.

第二部分的后半句,检查均值和方差分别为0,1,这一步如何做?我试着把标准化后的15个值求方差求出来是0.86.

1 个答案
已采纳答案

品职答疑小助手雍 · 2020年01月15日

这其实就是默认是标准化的一部分,标准正态分布的均值为0,标准差为1,那么把参数标准化的过程,也就是把这15个数值计算一下他们分别离均值有多少个标准差。

那1号举例,(-2.456-mean)/标准差=(-2.456+0.803)/2.6= -0.636

  • 1

    回答
  • 1

    关注
  • 391

    浏览
相关问题

NO.PZ2020010302000009 问题如下 Consir the following ta on a screte ranm variable X:Calculate the meanvarianof X. Stanrze X ancheththe meanvarianof X are 0 an1 respectively.Calculate the skew ankurtosis of X. The meis -0.803 anthe varianis 6.762.b.c.Hence, the skew of X is -0.581 anthe kurtosis of X is 2.773. 我看回答里需要准备一张标准正态的分布概率表,意思是考试我们把还需要带一张准备一张标准正态的分布概率表吗?

2024-01-14 12:30 1 · 回答

NO.PZ2020010302000009 问题如下 Consir the following ta on a screte ranm variable X:Calculate the meanvarianof X. Stanrze X ancheththe meanvarianof X are 0 an1 respectively.Calculate the skew ankurtosis of X. The meis -0.803 anthe varianis 6.762.b.c.Hence, the skew of X is -0.581 anthe kurtosis of X is 2.773. 如果在计算过程中,发现数字输或符号输入有误,怎样删除现有的错误数字或符号而不影响计算过程?

2024-01-07 18:42 1 · 回答

NO.PZ2020010302000009 问题如下 Consir the following ta on a screte ranm variable X:Calculate the meanvarianof X. Stanrze X ancheththe meanvarianof X are 0 an1 respectively.Calculate the skew ankurtosis of X. The meis -0.803 anthe varianis 6.762.b.c.Hence, the skew of X is -0.581 anthe kurtosis of X is 2.773. 具体怎么标准化的,能写出来标准化的具体过程么。谢谢

2023-08-04 10:14 2 · 回答

NO.PZ2020010302000009 问题如下 Consir the following ta on a screte ranm variable X:Calculate the meanvarianof X. Stanrze X ancheththe meanvarianof X are 0 an1 respectively.Calculate the skew ankurtosis of X. The meis -0.803 anthe varianis 6.762.b.c.Hence, the skew of X is -0.581 anthe kurtosis of X is 2.773. x stanrze什么意思?为啥表格下面variance的x stanrze是1?

2023-06-08 14:22 1 · 回答

NO.PZ2020010302000009问题如下Consir the following ta on a screte ranm variable X:Calculate the meanvarianof X. Stanrze X ancheththe meanvarianof X are 0 an1 respectively.Calculate the skew ankurtosis of X.The meis -0.803 anthe varianis 6.762.b.c.Hence, the skew of X is -0.581 anthe kurtosis of X is 2.773.手算还是计算器算,。

2023-05-06 16:45 1 · 回答