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.
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.