单项选择题
A.a probability function B.a random variable C.thee xpected value D.random function
A sample of 400 observations will be taken from an infi...
单项选择题A sample of 400 observations will be taken from an infinite population. The population proportion equals 0.8. The probability that the sample proportion will be greater than 0.83 is（）
A.0.4332 B.0.9332 C.0.0668 D.0.5668
From a population of 500 elements，a sample of 225 eleme...
单项选择题From a population of 500 elements，a sample of 225 elements is selected.It is known that the variance of the population is 900.The standard error of the mean is approximately（）
A.1.1022 B.2 C.30 D.1.4847
Given the following information：Standar ddeviation=8 Co...
单项选择题Given the following information：Standar ddeviation=8 Coefficient of variation=64% The mean would then be（）
A.12.5 B.8 C.0.64 D.1.25
