NO.PZ2020010304000048
问题如下:
Using the Excel function NORM.S.DIST or a normal prob-ability table, what are the critical values when testing the null hypothesis, , against
a. a one-sided lower alternative using a size of 10%?
b. a one-sided upper alternative using a size of 20%?
c. a two-sided alternative using a size of 2%?
d. a two-sided alternative using a size of .1%?
选项:
解释:
a. The lower-tailed critical value is -1.28.
b. The one-sided upper-critical value is 0.84.
c. A two-sided alternative with a size of 2% uses the same critical value as a one-sided upper test, which is 2.32. Each tail has probability 1% when using the critical value.
d. This size corresponds to the same critical value as a .05% upper-tailed test, which is 3.29.
看到您之前回答,有点似懂非懂。
“这题是一道查表题,所有的小问都可以通过查表解决。
第一问的是单尾累计10%的概率,那就查表找90%对应的概率,去负数就可以了(因为正态分布是对称的)
第二问问的是单尾20%的概率对应分位点,只不过是在均值右侧,所以是正值,直接找表里80%对应的值就行了。
第三问是双尾2%的概率,那对应的就是的单尾1%的概率(直接除以2),那就找表格里99%对应的分位点。
第四问是双尾0.1%,除以2就是对应单尾0.05%的概率,就去找99.95%对应的分位点就行了。”
(1)比如第一问是在z表里先找到0.9,再去定位到关键值吗,
(2)为什么涉及负数,这里的单复数怎么看
(可不可以把图画一下)
谢谢老师