开发者:上海品职教育科技有限公司 隐私政策详情

应用版本:4.2.11(IOS)｜3.2.5(安卓)APP下载

返回

vee · 2022年11月09日

不懂

  1. CFA I
  2. Quantitative

NO.PZ2015120604000137

问题如下：

Ida Lee and his team collect a lot of analysis of statistical data about the car market .According to the data, they come to the conclusion that the mean price of SUV is more than $46,435 in his country. Then they randomly select 64 SUVs whose mean price is $46,760. Assuming the standard deviation of the sample is 1370. Ida Lee conducts a hypothesis test to check their conclusion. At which significant level should Ida Lee reject the null hypothesis?

选项：

A.

0.5%.

B.

5%.

C.

1%.

解释：

B is correct.

If the significant level is 5%, the critical value=1.669<1.8978, Ida Lee should reject the null.

If the significant level is 0.5%, the critical value=2.656>1.8978, Ida Lee will fail to reject the null.

If the significant level is 1%, the critical value=2.387>1.8978, Ida Lee will fail to reject the null.


1.669

2.656怎么得到的，critical value什么意思

添加评论
vee · 2022年11月09日

是因为t分布表格得到的吗，看了一遍视频，好像明白了

2 个答案
已采纳答案

星星_品职助教 · 2022年11月09日

同学你好，

1.669、2.656、2.387都是critical value的概念，即拒绝域在横轴上所对应的关键值。critical value（关键值）都是查表（本题为t分布）得到的 。

如果计算出来的test statistic的绝对值 大于了 查表得到critical value的绝对值，则拒绝原假设。



_ Steven _ · 2023年05月28日

请问这题如何知道是差T分布表？如果是查T分布表题干也没有说明自由度是多少，请问如何查表？谢谢。我算出了1.8978，也选对了。但是对这里如何查对表很疑惑。

星星_品职助教 · 2023年05月28日

@ Steven _

1）本题里没有给出总体方差/标准差。根据“总体方差未知，用t分布”确定应该查t表。

2）本题为检验均值和一个确定的数字之间的关系。这个场景下的t分布自由度是n-1。可见教材截图：

由于n=64（they randomly select 64 SUVs），所以需要根据自由度为63来查表（但教材提供的t表没有63的数字，所以最后实际是根据最接近的自由度60来查的）。

  • 2

    回答

  • 0

    关注

  • 389

    浏览
相关问题

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.老师可否展示下这个题的完整解题过程已经回答的答案感觉说的都是局部。谢谢

2024-11-02 09:26 1 · 回答

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？

2024-08-23 09:44 2 · 回答

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

2024-08-16 17:43 1 · 回答

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。

2024-08-07 18:42 1 · 回答

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

2024-08-04 11:07 1 · 回答