PSYC 354 HOMEWORK 8

PSYC 354 HOMEWORK 8
Single-Sample T-Test
When submitting this file, be sure the filename includes your full name, course, and section.
Example: HW8_JohnDoe_354B01
Be sure you have reviewed this module/week’s lesson and presentations along with the practice
data analysis before proceeding to the homework exercises. Complete all analyses in SPSS, then
copy and paste your output and graphs into your homework document file. Answer any written
questions (such as the text-based questions or the APA Participants section) in the appropriate
place within the same file. Part I: Concepts Questions 1–3; Answer the questions in the spaces provided. Part I: Questions 1a–1g
Fill in the highlighted blanks with the best word or words. 1-a) You use a t-test when you know the population ________ but not the population
________. 1-b) In a single-sample t-test, the t-statistic indicates the distance of a sample mean
from the ________ in terms of estimated standard error units. 1-c) The 2 groups compared in the single-sample t-test are the sample and the
________. 1-d) The number of scores that are free to vary when you are estimating a population
parameter from a sample is called the ________. 1-e) A researcher reports the results of a single-sample t-test as t(12) = 2.78. The
degrees of freedom for this t-test are ______, which means there were ____ total
participants in the researcher’s sample. 1-f) Based on the t tables, the critical values of the t-statistic for a two-tailed test with
df = 17 and a p level of 0.01 are ________. 1-g) When your t-statistic in your results exceeds your critical cutoffs, you ________
the null hypothesis. Page 1 of 6 PSYC 354 Part I: Questions 2–3
2
) Explain what each part of the following statistical phrase represents, as it would be
reported in APA format: t(11) = 1.89, p = .06 3) t Answer 11 Answer 1.89 Answer P Answer .06 Answer Calculate the critical degrees of freedom and identify the critical t-value for a singlesample t-test in each of the following situations: 3-a) Two-tailed test, N = 13, p = .05 df = Answer 3-b) Two-tailed test, N = 26, p = .10 df = Answer 3-c) One-tailed test, N = 41, p = .01 df = Answer critical t = Answer
critical t = Answer
critical t = Answer Part II: SPSS Analysis Module/Week 8 Exercise File 1
Open the “Module/Week 8 Exercise File 1” document (found
in the course’s Assignment Instructions folder) in order to
complete these exercises. Page 2 of 6 PSYC 354 Part II:
Exercises 1–3
Use file: Module/Week 8 Exercise File 1 The anger scores for 6 fictional Marines following a month-long exercise are
entered in the Module/Week 8 Exercise File 1 document (found in the
Assignment Instructions folder).
Using these data, run 3 single-sample t-tests to compare the Marines’ mean
anger score to the following population values:
Population mean
anger scores
Population of college
men: = 7.9
Population of adult
men: = 9.2
Population of male
psychiatric
outpatients: = 11 For each test, paste the output and write a results section in current APA
style
o As demonstrated in the presentation and in the textbooks. There will be 3 sets of output and 3 results sections using this data set
o 1 for each test involving a different population mean. 1-a) Population of college men: = 7.9 Answer: SPSS output of the t-Test 1-b) Write a results section in current APA style describing the outcome.
All homework results sections must follow the example given in the SPSS
presentation. Results sections are paragraphs and must include the APAformatted statistical statement. Answer 2-a) Population of adult men: = 9.2 Page 3 of 6 PSYC 354 Answer: SPSS output of the t-Test 2-b) Write a results section in current APA style describing the outcome. See (1b)
for details. Answer 3-a) Population of male psychiatric outpatients: = 11 Answer: SPSS output of the t-Test 3-b) Write a results section in current APA style describing the outcome. See (1b)
for details. Answer Part III: SPSS Data Entry and Analysis Data provided below. Attitudes Toward
Technology Scale Scores
12
25
8
12
10
11
7
7
13
5
8
7
9
12
19
20
18 Part III:
Questions 1–2
Do elderly people have less positive attitudes toward technology than people in
general?
A social psychologist assessed the attitudes of 17 elderly people using a scale
where a lower score indicates a less positive attitude overall. The mean on this
scale for the general population is 15.6. The data for the participants are shown in
the table below.
Using SPSS, conduct a single-sample t-test to answer the social
psychologist’s research question. Page 4 of 6 PSYC 354 1-a)
Paste appropriate tabular output here
Answer: SPSS output of the t-Test 1-b)
Paste appropriate SPSS graph here
Answer: SPSS graph 2-a)
Write a results section in current APA style describing the outcome. Refer to earlier
directions for details of what is expected.
Answer: Part IV: Cumulative Data provided below for respective questions. Part IV: Questions 1a & 1b (Non-SPSS) Age at onset of dementia was determined in the general population to be = 67.8 and = 1.8. Use this information to answer the following:
Based on the data you have and the z-table, what percentage of people might 1-a) start to show signs of dementia at or before age 66?
Answer Work: 1-b) What two ages correspond to +/-1 z-score from the mean (i.e. a z-score of 1 and
Page 5 of 6 PSYC 354 -1)?
Answer (+1 z) Work: Answer (-1 z) Work: Part IV: Question 2a–2b (Non-SPSS)
For each of the following scenarios, compute the effect size and state whether it is
approximately small, medium, or large.
Participants in an inpatient study of treatment for OCD complete an anxious
feelings inventory which is then compared to the general population. 2-a) The sample mean is M = 22.
The mean in the general population of inpatients on this inventory is = 24.1,
and the population standard deviation is = 1.5. Effect Size: Answer Small/Med/Large: Answer 2-b) Work: A mood assessment in a sample of 15 gym members has a mean of M = 80.
The mean in the general population on this measure is = 77.9 with a standard
deviation of = 3.6. Effect Size: Answer Small/Med/Large: Answer Work: Submit Homework 8 by 11:59 p.m. (ET) on Friday of Module/Week 8. Remember to name file
appropriately. Done! Page 6 of 6