A.statisticB.populationC.parameterD.sampleMichael Bayle……

单项选择题Penny Bauer, Chief Financial Officer of Harrison Haulage, suspects irregularities in the payroll system, and orders an inspection of ‘each and every payroll voucher issued since 1 January 2005’. Five per cent of the payroll vouchers contained material errors. This is an example of （）.

A.nonparametric statistics
B.nominal data
C.descriptive statistics
D.inferential statistics

判断题Statistical independence means the outcome of one event is independent of the outcome of a second event.

判断题If the population distribution is unknown, in most cases the sampling distribution of the mean can be approximated by the normal distribution if the sample size is at least 15 observations.

判断题When analyzing categorical data, stem and leaf display is an appropriate plot.

单项选择题X is a discrete random variable that can have values from 0 to infinity, and occurrences of the events X counts are independent. The standard deviation of X is equal to the square root of the mean. The probability distribution of X is a(n) （）distribution.

A.binomial
B.uniform
C.normal
D.Possion