准备学统计学，书也是在论坛下载的：Understandable Statistics；发此贴是想记录我学习整本书的过程，也当监督自己。

我知道论坛里都是大侠，我刚接触统计学，如果在书中有不解的地方，还请坛子里的各位帮忙解答一下，在此深深谢过~

如果有跟我一样对统计学感兴趣的各位，我们一起讨论哈~

3/5：Chapter 1

section 1.3：

这题我这样答是准确的么？

6. Critical Thinking:In each of the following situations, the sampling frame does not match the population, resulting in undercoverage. Give examples of population members that might have been omitted.

(a) The population consists of all 250 students in your large statistics class. You plan to obtain a simple random sample of 30 students by using the sampling frame of students present next Monday.

---- 差额是在下周一没去上课的学生；拒绝参与的学生。

题目是在下周一上课的学生中随机抽样30个，那是不是没去上课的学生本身就不包含在里面了？那正好不在的学生是不是也可能导致样本的不完整？这题我不太懂。。

(b) The population consists of all 15-year-olds living in the attendance district of a local high school. You plan to obtain a simple random sample of 200 such residents by using the student roster of the high school as the sampling frame.

---- 差额包含刚好不在本地的学生，已经换电话号码的学生，拒绝回答的学生。