• What does it mean to set alpha at .05?
This question is asking you to say what the implications of alpha being .05 are. In other words, if I know that alpha is .05, what else do I know about this study? (Think in terms of hypothesis testing, Type 1 and Type II errors, critical region)
• What is your null hypothesis? Alternate hypothesis?
• Is this a one-tailed or two-tailed hypothesis?
HINT: always look at the Grading Criteria that is presented after the assignment instructions. This tells you exactly what you will be graded on. So, for this question you are required to identify the hypothesis as one- or two-tailed and explain why. Students often omit the last part and lose points.
• What is the critical z?
Be careful with this. The critical z (or criterion z) is NOT the z-score you calculate. This is covered in section 7.3 (PERFORMING THE z-TEST) of your text.
• Calculate the obtained z. Do you reject or fail to reject the null hypothesis?
You need to calculate the z-score using the formula in your lecture notes or text. Show your work! Once you have the obtained z, decide if this z leads you to reject or fail to reject the null hypothesis. Again, remember that you need to explain why.
• State in words what you have found.
After a decision is made, summarize the results of the hypothesis test. This should include your conclusion on whether there is enough evidence to support or reject the claim made in the research hypothesis. This should not be more than a sentence or two. Don't speculate about reasons that are not given in the assignment.; just state what the hypothesis was, what the results were and what your conclusion is.