The graph above shows the standard normal distribution for a right-tailed z-test with a critical value $z = 1.645$. The shaded area to the right represents the rejection region, where we reject the null hypothesis.

Would you like more details or have any questions?

Here are some related questions you might consider:

1. How would the critical value change for a two-tailed test with $\alpha = 0.05$?
2. What is the rejection region for a left-tailed test with $\alpha = 0.01$?
3. How do you calculate the p-value for a right-tailed z-test?
4. What happens if the test statistic falls outside the rejection region?
5. How does changing $\alpha$ affect the critical value in hypothesis testing?

Tip: Always check whether you're dealing with a one-tailed or two-tailed test, as this significantly changes the critical value and rejection region.