Part I: Concepts the questions in the spaces provided.
Part I: Questions1-7 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?
(State the 6 steps)
2) Using the z table in Appendix B (Table B-1) of Nolan and Heinzen (2016), calculate the following percentages for a z score of 0.95
2-a)% above this z score: Work:
2-b) % below this z score: Work:
2-c) At least as extreme as this z score (on either side):
Work:
3) Rewrite each of the following percentages as probabilities, or p levels:
3-a) 13%=
3-b) 78.2% =
3-c) 2% =
4) If the critical values, or cutoffs, for a two-tailed z test are -2.03 and +2.03, determine whether you would reject or fail to reject the null hypothesis in each of the following cases:
4a) z = 2.12
4b) z = -1.4
5) A group of 17men has an average height of M = 68.5 inches. We know that the population mean and standard deviation for men in the US is μ=69.1 inches, σ = 2.9 inches. (Note that this is a z statistic problem.)
5a) Calculate the z statistic for this sample (not the z score).
5b) How does this sample mean compare to the distribution of sample means?In other words, how does the height of the men in the sample compare to the height of men in the general population?
6) For the following scenarios, identify whether the researcher has expressed a directional or a nondirectional hypothesis:
6a)A psychologist wonders whether people who have traveled to another country score differently on the Big Five Inventory's "Openness to Experience" scale than people who have never traveled to another country.
6b)A researcher hypothesizes that young adults who take "selfies" more frequently exhibit higher levels of narcissistic personality traits than those who take "selfies" less frequently.
7) For the following scenario, state the null and research hypotheses in both words and symbolic notation. Symbolic notation must include the symbols "μ1" and "μ2" and a comparison operator (=, ≠, <, >, ≤, ≥), as described in Nolan and Heinzen (2014). Remember to consider whether the hypothesis is nondirectional or directional.
Hint: If you can't find these symbols in your word processing program, feel free to copy and paste them from the directions above.
Scenario:A school psychologist researches whether freshmen and seniors score differently on a measure of situational stress.
Null Hypothesis (H0): Symbolic Notation
Null Hypothesis:
Written Statement
Research Hypothesis (H1): Symbolic Notation
Research Hypothesis:
Written Statement
Part I: Questions 8a-8g
Fill in the highlighted blanks with the best word or words.
8-a) Values of a test statistic beyond which you reject the null hypothesis are called ________.
8-b) The ________is the area in the tails in which the null can be rejected.
8-c) The probability used to determine the critical values, or cutoffs, in hypothesis testing is known as a ________ level, also known as alpha.
8-d) If your data differ from what you would expect if chance were the only thing operating, you would call your finding ________.
8-e) A hypothesis test in which the research hypothesis is directional is a(n) ________test.
8-f) 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.
8-g) If your z-statistic exceeds the critical cutoff, you can ________the null hypothesis.
Part I: Questions 9a-9d
The verbal part of the Graduate Record Exam (GRE) has a μ= 500 and σ = 100.Use the normal distribution and the formulas and steps in this week's presentations to the following questions:
Note: Showing work is required for this section.Remember that it helps to transfer the raw mean and SD from the description above to the standardized curve shown here (though you don't need to show this). This helps compare raw and z scores and check your work.
9a) What is the z score for a GRE score of 630?
What is the percentile rank of this z score?(Hint: See slide 7 of this week's related presentation)
(z score): Work (required):
(percentile): Work (required):
9b) What GRE score corresponds to a percentile rank of 39%?(Hint: See slide 17 of this week's related presentation)
Work (required):
9c) If you wanted to select only students at or above the 87thpercentile, 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)
Work (required):
9d) What is the z score for a GRE score of 321?
Work (required):
Part II: SPSS Analysis
For this section, you will be using last module/week's data set containing IQ scores.
Open the file; it should also contain the standardized IQ variable you created last module/week.
Part II:
Question 1a&1b
Open last week's homework file that you modified and were told to save (Module 5 Exercise File 1) containing IQ scores and z scores._
• Using the z-scored IQ variable, create percentile ranks assuming the scores are normally distributed.
o Call the new percentile variable "IQrank."
1a) List the first 5 ranks from your file (rows 1-5). Remember that the data should be in the same order as it was when it was downloaded. (You can always download the file again from Blackboard to check.)
:
Row 1:
Row 2:
Row 3:
Row 4:
Row 5:
1b) Which raw IQ score seems to best divide the top 50% from the bottom 50% of scores in this sample?
(This score can be found by looking carefully over the values in the IQ rank column)
Part III: SPSS Data Entry and Analysis
There is no Part III material this module/week.
Part IV: Cumulative
Part IV: (Non-SPSS)
Questions 1-4
For a distribution with M = 149 and s = 10:
1) What is the z-score corresponding to a raw score of 157?
Work:
2) What is the z-score corresponding to a raw score of 122?
Work:
3) If a person has a z-score of -1.7, what is his/her raw score?
Work:
4) If a person has a z-score of 0.35, what is his/her raw score?
Work:
Part IV: (Non-SPSS)
Questions5-8_______
For the following types of data, state the graph that would be the best choice to display the data.
Two items have more than one correct -for these, either is acceptable.
5) A nominal independent variable (IV) and a scale dependent variable (DV)
6) One scale variable with frequencies (when you want to see the general shape of the distribution).
7) One scale IV and one scale DV
8) One nominal variable broken down into percentages