Comparing Two Means: Drink-Driven Student's Statistics Adventure

The assignment requires students to analyze data from a study comparing two exercise programs: walking alone versus walking combined with strength training. Participants' aerobic endurance was measured before and after six months of exercise. Using SPSS, students will run an independent sa...Read More

PUBH 6033—Week 7 Assignment 1
Comparing two means: When drink drove a student to statistics
(Rubric included)
Instructions
For this assignment, you review this week’s Learning Resources and then perform a two-sample
independent t test and an ANOVA related to the dataset that was utilized in the week 2 SPSS
application assignment. Import the data into SPSS; or, if you correctly saved the data file in
Week 2, you may open and use that saved file to complete this assignment. Type your answers
to all questions directly into the worksheet, and paste the required output at the end of this
document.
Submit this Application Assignment by Day 7.
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Research Scenario
A study was conducted to determine if a walking plus strength training exercise program results
in a significantly greater increase in aerobic capacity as compared to a walking only exercise
program. Participants are randomly selected and then randomly assigned to one of the
exercise groups. Participants’ aerobic endurance was assessed at the beginning of the study
and, again, after 6-months of exercise.
Coding for study variables:
 AGE—age in years
 SEX—1 =male, 2=female
 EXERCISE—1= walking and strength training; 2 = walking;
 CHNG_ENDUR—change in maximal oxygen uptake (liters per minute) from pre-test to
post-test
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Note: Save all of your SPSS output. You will paste copies in Steps 7–9, below.
Step 1: Review this week’s Learning Resources.
Step 2: Import the Microsoft Excel data file provided in this week’s Learning Resources into
SPSS (or open saved file from Week 2 Application Assignment).
Step 3: Run and save the Codebook for your SPSS data file
Step 4: Conduct an independent samples t test to determine if there is a difference between
the exercise type 1 in terms of changes in maximal oxygen uptake. Note that the independent
variable is EXERCISE, and the dependent variable is CHNG_ENDUR. For this analysis, choose a
two-tailed test of significance.
© 2017 Laureate Education, Inc. Page 1 of 5

Step 5: Conduct a between-subjects ANOVA to determine if there is a difference between sex
(males vs. females) and CHNG_ENDUR. Note that the independent variable is SEX, and the
dependent variable is CHNG_ENDUR. For this analysis, choose a two-tailed test of significance.
Step 6: Review your SPSS output and answer each of the following questions:
QUESTION type answers below Score (to be entered
by instructor)
From the independent samples t-test output:
1. What is the mean CHNG_ENDUR for group 1? ____4.85____________ ____ / 3 points
2. What is the CHNG_ ENDUR standard deviation
for group 1? ____1.424____________ ____ / 3 points
3. What is the mean CHNG_ENDUR for group 2? 3.50________________ ____ / 3 points
4. What is the CHNG_ ENDUR standard deviation
for group 2? _1.821_______________ ____ / 3 points
5. What is the value of the t statistic (equal
variances assumed)? ______2.611__________ ____ / 3 points
6. What is the probability that the obtained t
statistic was simply due to chance as opposed
to actual exercise type differences [see “Sig
(two-tailed)” on output]?
______0.013__________ ____ / 3 points
7. Are the results statistically significant at alpha =
0.05 (yes or no)? _____Yes___________ ____ / 3 points
8. Based on the results, do you reject or fail to
reject the null hypothesis?
____reject null
hypothesis____________ ____ / 3 points
From the ANOVA output:
9. What is the mean CHNG_ENDUR for males? ____4.32____________ ____ / 3 points
10. What is the CHNG_ENDUR standard deviation
for males? _______1.729_________ ____ / 3 points
11. What is the mean CHNG_ENDUR for females? ______4.00__________ ____ / 3 points
12. What is the CHNG_ENDUR standard deviation
for females? _____1.815___________ ____ / 3 points
13. What is the calculated F-value? ______0.321__________ ____ / 3 points
14. What is the probability (noted as “Sig” on
output) that the obtained F-value was simply
due to chance as opposed to actual gender
differences?
____0.575____________ ____ / 3 points
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Step 7: Paste the SPSS Codebook output below.
T test
T-TEST GROUPS=EXERCISE(1 2)
/MISSING=ANALYSIS
/VARIABLES=CHNG_ENDUR
/CRITERIA=CI(.95).
ANOVA
ONEWAY CHNG_ENDUR BY SEX
/STATISTICS DESCRIPTIVES
/MISSING ANALYSIS.
Step 8: Paste the independent samples t-test output below.
Results from t test
Group Statistics
EXERCISE N Mean Std. Deviation Std. Error Mean
CHNG_ENDUR walking and strength training 20 4.85 1.424 .319
walking 20 3.50 1.821 .407
Independent Samples Test
Levene's Test
for Equality of
Variances
t-test for Equality of Means
F Sig. t df Sig.
(2-
tailed)
Mean
Difference
Std. Error
Difference
95%
Confidence
Interval of the
Difference
Lower Upper
CHNG_ENDUR Equal
variances
assumed
.343 .562 2.611 38 .013 1.350 .517 .303 2.397
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Equal
variances not
assumed
2.611 35.918 .013 1.350 .517 .301 2.399
Step 9: Paste the ANOVA output below.
Results from ANOVA test
Descriptives
CHNG_ENDUR
N Mean Std. Deviation Std. Error 95% Confidence Interval for
Mean
Minimum Maximum
Lower Bound Upper Bound
male 22 4.32 1.729 .369 3.55 5.08 2 8
female 18 4.00 1.815 .428 3.10 4.90 1 8
Total 40 4.18 1.752 .277 3.61 4.74 1 8
ANOVA
CHNG_ENDUR
Sum of Squares df Mean Square F Sig.
Between Groups 1.002 1 1.002 .321 .575
Within Groups 118.773 38 3.126
Total 119.775 39
Section below (scoring) is to be completed by Instructor
Scoring Rubric for Week 2 Assignment 1—Hands on SPSS (60 points)
Questions
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14 questions (worth 3 points each)
____ / 42 points possible
SPSS Output
Three SPSS outputs (6 points each) ____ / 18 points possible
Initial Score (60 possible points):
Timeliness Factor (late points deducted):
Total Score (60 possible points):
Instructor comments:
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