- 1) You are a research intern at Oregon Health Sciences University. You are responsible for determining whether there is a statistically significant difference in the systolic blood pressure readings of four groups of individuals diagnosed with hypertension. The first group took medication, the second group exercised, and the third group followed a special diet. The fourth group received no intervention. What kind of test would be appropriate to determine whether the there is a statistically significant difference in the systolic blood pressure readings of the four groups? Explain your answer. Please develop appropriate null and alternate hypotheses for this question.
- 2) You work in the Institutional Research department of the University of Portland. Your job is to conduct research and compute statistics related to the academic activities on campus.
- a) The Provost has asked you whether there is a statistical difference in the average GPAs
across the 5 Colleges (CAS; Business; Education; Engineering; Nursing). There are 2,355 undergraduate students. You recognize this question can be answered by conducting a One-Way Analysis of Variance procedure. What are your degrees of freedom?
- b) The Chair of the Department of Sociology and Social Work has asked you whether there is a statistical difference in the average GPAs of Social Work majors, Sociology majors, and Criminology Track students. There are 81 students in the department. You recognize that this question can be answered by conducting a One-Way Analysis of Variance procedure. What are your degrees of freedom?
- 3) For her senior psychology capstone research project, Rhonda asked 22 UP students about the number of hours they spend studying during a typical school week. The students have different housing arrangements: on campus, off-campus, or living with parents.
- a) If Rhonda wants to determine whether there is a statistically significant effect of
housing arrangement on average study time, at the 0.05 confidence level, what is the
critical value of F to which she will compare her computed F-ratio?
- b) What if she only talked to 12 students? What would be the critical value of F?
- c) What if she talked to 8 students, but she wanted to use a 0.01 confidence interval?
What would be the critical value of F in that case?
- 4) A graduate student in a Public Planning program hypothesizes that there is a significant effect of metropolitan location on commuting time. Independent random samples were
obtained from workers who commute to work during the 8:00am rush hour. The following data were obtained from individual workers in the following 6 cities; commuting times of each person are reported in minutes.
Atlanta
|
Boston
|
Dallas
|
Philadelphia
|
Seattle
|
St. Louis
|
29
|
18
|
42
|
29
|
30
|
15
|
21
|
37
|
25
|
20
|
23
|
24
|
20
|
37
|
36
|
33
|
31
|
42
|
15
|
25
|
32
|
37
|
39
|
23
|
37
|
32
|
20
|
42
|
14
|
33
|
26
|
34
|
26
|
|
|
18
|
|
48
|
35
|
|
|
|
- a) Identify your null hypothesis.
- b) Perform a one-way ANOVA using SPSS. Copy and paste the relevant output for your
instructor to review and interpret the results to answer the question. Is there significant evidence to reject the null hypothesis that commuting time is the same for all 6 metropolitan areas? Use alpha = 0.05.
- c) If you reject the null, perform and discuss a post-hoc analysis to identify the group pairings that lead you to your conclusion.
5) The sociologist Mark Warr (2002) has argued that peer influence has a strong effect on rates of delinquency. Drawing upon this insight, a UP sociology/criminology track student elected to use Add Health in a study to determine whether the amount of time youths spend time with friends has an effect on delinquency. Please replicate a portion of this student’s study by using our Add Health data to examine the mean levels of delinquency reported by youths who reported spending different amounts of time “hanging out with friends” in the week prior to the survey.
- a) Identify your null hypothesis.
- b) Perform a one-way ANOVA using SPSS. Copy and paste the relevant output for your
instructor to review, and interpret the results to answer the question.
- c) If you reject the null, perform a post-hoc analysis to identify the group pairings that lead
you to your conclusion.
6) In a previous homework assignment, students conducted an independent-samples t-test procedure to determine whether there was a statistically significant difference between White youths and non-White youths in the amount of weekly allowance they received from parents. For this question, please use our Add Health sample to evaluate the following research hypothesis:There is an effect of RACE on the amount of weekly allowance youths receive from their parents. (Use the 6-category RACE variable that is constructed in your SPSS syntax.)
- a) Identify your null hypothesis.
- b) Perform a one-way ANOVA using SPSS. Should you reject or accept the null hypothesis,
based on these results?
- c) If you reject the null, perform a post-hoc analysis to discover the group pairings that
lead you to your conclusion.