商务统计学章节测试课后答案2024春

第七章测试

1.As a general rule, the normal distribution is used to approximate the sampling distribution of the sample mean only if
A:the sample size n is sufficiently large B:np and n(1 – p) are both greater than 5 C:the sample mean is close to 0.50. D:the underlying population is normal
答案:A
2.The eight employees of the Art Department and their ‘years of experience’ are listed in the following table. EmployeeABCDEFGHExperience (years)1021115748 If a sample of three employees is selected with replacement, the number of elementary outcomes in the sample space is _______________.
A:56 B:64 C:336 D:512 3.A sampling distribution is a distribution of _______________.
A:excess profits to selected shareholders. B:a population parameter, such as, µ. C:a sample statistic, such as, D:a population attribute, such as, employee’s age. 4.The standard deviation of a sampling distribution is commonly called _______.
A:statistical leverage. B:statistical margin. C:the uniform spread. D:the standard error. 5.The central limit theorem states that if n is large enough, the distribution of the sample means is _____________ distributed regardless of the shape of the population.
A:uniformly B:approximately normally C:nonrandomly D:randomly 6.According to the central limit theorem, the mean of the sample means for a given size of sample is equal to _______.
A:the population mean B:the population mean divided by the square root of n C:zero D:the population mean divided by n 7.Increasing the sample size causes the standard error of the mean to ________.
A:destabilise in value B:seek market equilibrium C:decrease in value D:increase in value 8.Increasing the sample size causes the sampling distribution of  to ________.
A:shift to the left B:have more dispersion C:have less dispersion D:shift to the right 9.Suppose a population has a mean of 90 and a standard deviation of 28. If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a mean of more than 95 is _______.
A:0.4286 B:0.3944 C:0.8944 D:0.1056 10.Suppose 40% of all university students have a computer at home and a sample of 64 is taken. What is the probability that more than 30 of those in the sample have a computer at home?
A:0.3686 B:0.1314 C:0.8686 D:0.6314