SPSS Hypothesis Testing
Instructions
For this assignment, you perform a two-sample independent t-test, an ANOVA, and a correlation analysis related to the
datasetthat has been utilized in the previous two modules. Import the data into SPSS or, if you correctly saved the data
file from the Module 4 and 5Assignments, 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 of Week 11.
Research Scenario
A researcher is interested in the effect of a new medication on serum cholesterol, HDL cholesterol, and glycosylated
hemoglobin of adults. The researcher randomly selects a sample of 40 (20 male and 20female) participants who have
been diagnosed with high cholesterol. Assuring equal distribution of males and females, the participants are randomly
assigned to one of two conditions (or groups): Following pretest measures of serum cholesterol (chol), high-density
lipoprotein cholesterol (HDL), and glycosylated hemoglobin (glyhb), the experimental group (Group 1) is given the
medication for a period of 6months while the control group (Group 2) is given a placebo. After the 6months,chol, HDL,
and glyhb are again measured.
The posttest data for each participant are provided in the Module 4 Application Assignment Data SetExcel fileand can be
found in the Module 6 Learning Resources. The codebook for the data provided is as follows:
AGE Age in years
SEX 1 =male, 2=female
GROUP 1 =medication, 2=placebo
CHNG_CHOL change in cholesterol from pretest to posttest
HDL High-density lipoprotein at posttest
GLYHB Glycosylated hemoglobin at posttest
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Step 1: Import the Microsoft Excel data file into SPSS or use the correct saved SPSS data file as noted in the instructions
above.
Step 2: Conduct an independent samples t-test to determine if there is a difference between Group 1 (medication) and
Group 2 (placebo) in terms of changes in cholesterol values. Note that the independent variable is GROUP, and the
dependent variable is CHNG_CHOL .For this analysis, choose a two-tailed test of significance. (Be sure to save your
output.)
Step 3: Conduct a between-subjects ANOVA to determine if there is a difference between sex (males vs. females) and
HDL. Note that the independent variable is SEX, and the dependent variable is HDL. For this analysis, choose a two-
tailed test of significance. (Be sure to save your output.)
Step 4: Conduct a Pearson correlation to determine if there is a relationship between HDL and GLYHB. For this analysis,
choose a two-tailed test of significance. (Be sure to save your output.)
Step 5: Review your SPSS output and answer each of the following questions:
From the independent samples t-test output:
A. What is the mean CHNG_CHOL for Group 1? -5.95
B. What is the CHNG_CHOL standard deviation for Group 1? ______4.095 C. What is the mean CHNG_CHOL for Group 2? ___-.45
D. What is the CHNG_CHOL standard deviation for Group 2? ___1.395 E. What is the calculated t-score (equal variances assumed)? ___– 5.376
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F. What is the probability that the obtained t-score was simply due to chance as opposed to actual gender differences
[see “Sig (two-tailed)” on output]? _________0.00
G. If the probability associated with the obtained t-score is <0.05, we assume the results (difference in mean
CHNG_CHOL between groups) are much more likely due to the effects of the medication than to chance. In other
words, we would say the results are statistically significant. Are the results statistically significant (yes or no)?
_________No
From the ANOVA output:
H. What is the mean HDL for group males? _________40.85
I. What is the HDL standard deviation for males? _________7.788
J. What is the mean HDL for group females? _________49.30
K. What is the HDL standard deviation for females? _________7.477
L. What is the calculated F-value? __________12.251
M. 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? __________0.01
From the correlation output:
N. What is the Pearson correlation score for HDL and GLYHB? – 587
O. What is the direction of the correlation value and what does this mean? __ The direction of the correlation is
negative. This implies that as HDL increase, GLYHB decreases and vice versa is true
P. What is the probability for the obtained Pearson correlation score [see “Sig (two-tailed)” on output]? _significant at
0.01 (2-tailed)
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Q. If the probability associated with the Pearson correlation is <0.05, we assume a significant relationship. Is there a
significant relationship between HDL and GLYHB? _________No
Step 6: Paste all required SPSS output below.
T test
Group Statistics
GROUP N Mean Std. Deviation Std. Error Mean
CHNG_CHOL 1 20 -5.65 4.095 .916
2 20 -.45 1.395 .312
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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_CHO
L
Equal variances
assumed
13.247 .001 -5.376 38 .000 -5.200 .967 -7.158 -3.242
Equal variances not
assumed
-5.376 23.349 .000 -5.200 .967 -7.199 -3.201
One way ANOVA
Descriptive
HDL
N Mean Std. Deviation Std. Error 95% Confidence Interval for Mean Minimum Maximum
Lower Bound Upper Bound
males 20 40.85 7.788 1.742 37.20 44.50 28 56
females 20 49.30 7.477 1.672 45.80 52.80 39 69
Total 40 45.08 8.666 1.370 42.30 47.85 28 69
ANOVA
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HDL
Sum of Squares df Mean Square F Sig.
Between Groups 714.025 1 714.025 12.251 .001
Within Groups 2214.750 38 58.283
Total 2928.775 39
Correlations
HDL GLYHB
HDL Pearson Correlation 1 -.587 **
Sig. (2-tailed) .000
N 40 40
GLYHB Pearson Correlation -.587 ** 1
Sig. (2-tailed) .000
N 40 40
**. Correlation is significant at the 0.01 level (2-tailed).