问题如下图：
选项：
A. 
B. 
C. 
请问，(1)这道题目是右侧单边检验还是左侧单边检验?
(2)这道题目，查t分布，应该自由度为63，然后用单侧5%、0.5%、1%，查出来的数字跟答案的关键值都不一样，这个是怎么回事？
星星_品职助教 · 2019年11月04日
同学你好，
这道题的拒绝域应该在右尾，但其实无论是左尾还是右尾其实都不会影响最终的结果，只要计算出来的t统计量的绝对值大于临界值，就拒绝。
T临界值的自由度是63没问题的，不过一般的表都不会延伸到63这么长，原版书给的附表自由度也是只到60。但因为这道题样本容量很大，t分布趋近于正态分布，所以可以简单的用正态分布的值（n很大时和t差距微乎其微）来做判断，例如单侧5%为1.645，1%为2.33, 0.5%为2.58等。不会影响结果的。
但如果在真实的考试中，具体的t critical value是会给出的。以5%单尾为例，很可能出题形式为直接给出t（64,5%）的值，t（63,5%）的值，t（63,10%）的对应值等等，让考生去自行选择用哪一个。会选即可。加油
denzel wu · 2019年12月01日
假设考试给出这些值， t（64,5%）的值，t（63,5%）的值，t（63,10%) , 那它默认表示单尾的值还是双尾的值？
星星_品职助教 · 2019年12月01日
考试时候的出题非常严谨，需要的信息都会告知的。到时候用的是单尾还是双尾题干会说的，不用担心~
NO.PZ2015120604000137 问题如下 I Lee anhis tecollea lot of analysis of statisticta about the cmarket .Accorng to the tthey come to the conclusion ththe mepriof SUV is more th$46,435 in his country. Then they ranmly sele64 SUVs whose mepriis $46,760. Assuming the stanrviation of the sample is 1370. I Lee concts a hypothesis test to chetheir conclusion. whisignificant level shoulI Lee rejethe null hypothesis? A.0.5%. B.5%. C.1%. B is correct.If the significant level is 5%, the criticvalue=1.669 1.8978, I Lee shoulrejethe null.If the significant level is 0.5%, the criticvalue=2.656 1.8978, I Lee will fail to rejethe null.If the significant level is 1%, the criticvalue=2.387 1.8978, I Lee will fail to rejethe null. 请问此题需要记住t-test表的5%、1%、0.5%对应的数值吗？
NO.PZ2015120604000137问题如下 I Lee anhis tecollea lot of analysis of statisticta about the cmarket .Accorng to the tthey come to the conclusion ththe mepriof SUV is more th$46,435 in his country. Then they ranmly sele64 SUVs whose mepriis $46,760. Assuming the stanrviation of the sample is 1370. I Lee concts a hypothesis test to chetheir conclusion. whisignificant level shoulI Lee rejethe null hypothesis?A.0.5%.B.5%.C.1%.B is correct.If the significant level is 5%, the criticvalue=1.669 1.8978, I Lee shoulrejethe null.If the significant level is 0.5%, the criticvalue=2.656 1.8978, I Lee will fail to rejethe null.If the significant level is 1%, the criticvalue=2.387 1.8978, I Lee will fail to rejethe null.备择假设是小于，不应该是分布函数左侧面积，应该是小于关键值才才拒绝吗
NO.PZ2015120604000137 问题如下 I Lee anhis tecollea lot of analysis of statisticta about the cmarket .Accorng to the tthey come to the conclusion ththe mepriof SUV is more th$46,435 in his country. Then they ranmly sele64 SUVs whose mepriis $46,760. Assuming the stanrviation of the sample is 1370. I Lee concts a hypothesis test to chetheir conclusion. whisignificant level shoulI Lee rejethe null hypothesis? A.0.5%. B.5%. C.1%. B is correct.If the significant level is 5%, the criticvalue=1.669 1.8978, I Lee shoulrejethe null.If the significant level is 0.5%, the criticvalue=2.656 1.8978, I Lee will fail to rejethe null.If the significant level is 1%, the criticvalue=2.387 1.8978, I Lee will fail to rejethe null. 这是一个技术测试，谢谢。
NO.PZ2015120604000137 问题如下 I Lee anhis tecollea lot of analysis of statisticta about the cmarket .Accorng to the tthey come to the conclusion ththe mepriof SUV is more th$46,435 in his country. Then they ranmly sele64 SUVs whose mepriis $46,760. Assuming the stanrviation of the sample is 1370. I Lee concts a hypothesis test to chetheir conclusion. whisignificant level shoulI Lee rejethe null hypothesis? A.0.5%. B.5%. C.1%. B is correct.If the significant level is 5%, the criticvalue=1.669 1.8978, I Lee shoulrejethe null.If the significant level is 0.5%, the criticvalue=2.656 1.8978, I Lee will fail to rejethe null.If the significant level is 1%, the criticvalue=2.387 1.8978, I Lee will fail to rejethe null. 本题总体方差未知使用t检验，自由度是n-1，那计算标准误是使用n还是n-1
NO.PZ2015120604000137 问题如下 I Lee anhis tecollea lot of analysis of statisticta about the cmarket .Accorng to the tthey come to the conclusion ththe mepriof SUV is more th$46,435 in his country. Then they ranmly sele64 SUVs whose mepriis $46,760. Assuming the stanrviation of the sample is 1370. I Lee concts a hypothesis test to chetheir conclusion. whisignificant level shoulI Lee rejethe null hypothesis? A.0.5%. B.5%. C.1%. B is correct.If the significant level is 5%, the criticvalue=1.669 1.8978, I Lee shoulrejethe null.If the significant level is 0.5%, the criticvalue=2.656 1.8978, I Lee will fail to rejethe null.If the significant level is 1%, the criticvalue=2.387 1.8978, I Lee will fail to rejethe null. 这个t表 考试会给么 会明确表格是单尾还是双尾吗