Rejection region from a population

Here is the problem:

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Suppose that we draw a random sample of 35 observations from a population and test, at alpha = .05, H0 : ? <= 24 vs Ha : ? > 24. Which of the following is the correct rejection region?

1. ? z > 1.96
2. ? z > 1.645
3. ? z < ? 1.645
4. ? z > 2.326

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I have a ti-83 calculator and I have literally tried every test under stat but all of them want a mean. I know n=35 and I understand the null and alternative hypothesis but I just have no idea how to start this problem because I don't know the mean. Can anyone help me please? Thank you!!

The mean is given to you in the problem. It is 24.

That is what you're testing. \(\displaystyle {\mu}\) is the mean in your hypothesis test.