Part I: Questions 1-7
Answer the following questions.
If applicable, remember to show work in your homework document for partial credit
1) What are the 6 steps of hypothesis testing?
2) Using the z table in Appendix B, calculate the following percentages for a z score of -0.45
3) Rewrite each of the following percentages as probabilities, or p levels:
4) If the critical values, or cutoffs, for a two-tailed z test are -2.05 and +2.05, determine whether you would reject or fail to reject the null hypothesis in each of the following cases:
5) Imagine a class of twenty-five 12-year-old girls with an average height of 62 inches. We know that the population mean and standard deviation for this age group of girls is m=59 inches, s = 1.5 inches. (Note that this is a z statistic problem.)
6) For the following scenarios, identify whether the researcher has expressed a directional or a nondirectional hypothesis:
7) For the following scenario, state the null and research hypotheses in both words and symbolic notation. Symbolic notation must include the symbols “m1” and “m2” and a comparison operator (=, , <, >, , ), as described in Nolan and Heinzen (2014). Remember to consider whether the hypothesis is nondirectional or directional.
Part I: Questions 8a-8g
Fill in the highlighted blanks with the best word or words
Values of a test statistic beyond which you reject the null hypothesis are called
The is the area in the tails in which the null can be rejected.
The probability used to determine the critical values, or cutoffs, in hypothesis testing is known as a level, also known as alpha.
If your data differ from what you would expect if chance were the only thing operating, you would call your finding._____.
A hypothesis test in which the research hypothesis is directional is a(n) test.
A hypothesis test in which the research hypothesis specifies that there will be a difference but does not specify the direction of that difference is a(n) test.
If your z-statistic exceeds the critical cutoff, you can the null hypothesis.
What is the z score for an officer who is 72 inches tall? Based on the z score and the z table, what is the officer’s percentile? (Hint: See slide 7 of this week’s related presentation)
What is the height (in inches) that marks the 80thpercentile for this group of officers? (Hint: See slides 14-16 of this week’s related presentation)
What percent of officers are between 68 and 72 inches tall? (Hint: See slide 12 of this week’s related presentation)
What is the z score for a GRE score of 583?
What is the percentile rank of this z score? (Hint: See slide 7 of this week’s related presentation)
What GRE score corresponds to a percentile rank of 25%? (Hint: See slide 17 of this week’s related presentation)
If you wanted to select only students at or above the 82nd percentile, what GRE score would you use as a cutoff score (i.e. what GRE score corresponds to this percentile)? (Hint: See slides 14-16 of this week’s related presentation)