1. The Dean of Students malled a survey to a total of 400 students. The sample included 100 students randomly selected from each of the freshman,sophomore,junior,and serior classes on campus last term. What sampling method was used? (a)systematic sample (b)simple random sample (c)cluster sample (d)stratified sample 2. An airport has been criticized for the waiting times associated with departing flights. While the critics acknowledge that man flights have little or no waitting times, their complaints deal more specifically with the longer waits attributed to some flights. The critics are interested in showing, mathematically,exactly what the problems are. Which type of distribution would best model the waiting times of the departing flights at the Airport? (a)uniform distribution (b)normal distribution (c)binomial distribution (d)exponential distribution 3. The standard error of the mean (a)measures the variability of the mean from sample to population. (b)is never larger than the standard deviation of the population. (c)decreases as the sample size increases. (d)all of the above 4. When extreme values are present in a set of data, which of the following descriptive summary measures are most approprlate? (a)CV and range (b)variance and interquartile range (c)arithmetic mean and standard deviation (d)interquartile range and median 希望题目没打错.... 因为题目英文字很不清楚 希望帮我解答的人可以小小解释一下为什麽会选择那个答案^^ 谢谢 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 118.161.226.165