课程名称︰统计导论 课程性质︰数学系选修 课程教师︰江金仓 开课学院：理学院 开课系所︰数学系 考试日期（年月日）︰2016.10.24 考试时限（分钟）：50 试题 : Introduction to Statistics (Test 1) 1.(15%) Classify the measurement scales of the following variables. (1a) religious affiliation. (1b) grade point average. (1c) intelligence quotient. (1d) salary. (1e) latitude. 2.(20%) For each of the following situations, state which type of sampling plan was used. (2a) An airline company made a list of all its flights and randomly selected 25 flights. All of the passengers on those flights were aske to fill out a survey. (2b) A pollster divided a city into city blocks and surveyed the third house to the west southeast corner of each block. (2c) An university divided employees into three categories: staff, faculty, and student employees. A random sample was selected from each group and they were telephoned and asked for their opinions. (2d) The store posted an interviewer at the door and told her to collect a sample of 100 opinions by asking the next person who came in the door each time she had finished an interview. 3.(20%) Distinguish between each of the following paired terms. (3a) retrospective study versus prospective study. (3b) confounding variable versus interacting variable. (3c) categorical variable versus discrete variable. (3d) case-control study versus matched-paired design. 4.(20%) Compute the mean, median, mode, and variance of the grouped data with f_1, f_2,...,f_g being the frequencies of the g classes [a_0,a_1),[a_1,a_2),.. ,[a_(g-1),a_g]. 5.(15%) Try to mark the relative positions of mean, median, and mode of bell- shaped, right skewed, and left skewed distributions, respectively. 6.(3%)(7%) Consider the data of thirteen ninth-year students in Sydney using conventional instructional material. The number of seconds, required to arrive at a solution, are recorded for the students. Each student was allotted at most 5 minutes to nswer a question. Is the measure of average appropriate for the considered data? Explain your answer. Data: 130, 139, 146, 150, 161, 177, 228, 242, 265, 300+, 300+, 300+, 300+. (Note: t+ represents the required time more than t seconds.) --

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