Which of the following statements are not true if a test procedure about the population mean $\mu$ is performed when the population is normal with known standard deviation $\sigma$ ?
A) The rejection region for level $\alpha$
Test is $z \geq z _ { \alpha}$
If the test is an upper-tailed test.
B) The rejection region for level $\alpha$
Test is $z \geq z _ { \alpha / 2 }$
If the test is an upper-tailed test.
C) The rejection region for level $\alpha$
Test is $z \leq - z _ { \alpha }$
If the test is a lower-tailed test.
D) The rejection region for level $\alpha$
Test is either $z \geq z _ { \alpha/ 2 }$
Or $z \leq - z _ { \alpha/2 }$
If the test is a two-tailed test.
E) None of the above statements are true.

Question

Quizplus · Accepted Answer

In an upper-tailed test, the rejection region is defined for values greater than a certain critical value, but it uses $z_{\alpha}$, not $z_{\alpha/2}$. Statement B incorrectly describes the rejection region for an upper-tailed test by using $z_{\alpha/2}$ instead of $z_{\alpha}$.

Which of the Following Statements Are Not True If a Test