Statistics Exercise 16 and 17

This article covers Exercise 16 and 17 in Statistics, discussing degrees of freedom, means and standard deviations, t-value and p-value, assumptions, clinical benefits, and study findings. It includes a detailed analysis of the statistical tests used, null hypotheses, and the clinical importance of the results. The article also provides a rationale for the assumptions made and discusses the implementation of the study findings in practice.

Statistics
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22nd August 2018
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Exercise 16
1. What do degrees of freedom (df ) mean? Canbulat et al. (2015) did not provide the df s in
their study. Why is it important to know the df for a t ratio? Using the df formula,
calculate the df for this study.
Answer
Degrees of freedom (df ) refers to the number of values that are normally assigned to
statistics distribution. It is crucial to know the df for a t-ratio so as to determine if the data
in a t-distribution table is significant or not at a certain level of significance.
The df for this study is:
df =(88+ 88)−2=174
2. What are the means and standard deviations (SDs) for age for the Buzzy intervention and
control groups? What statistical analysis is conducted to determine the difference in means
for age for the two groups? Was this an appropriate analysis technique? Provide a
rationale for your answer.
Answer
Group Mean Standard deviation
(SD)
Buzzy group 8.25 1.51
Control Group 8.61 1.69
The statistical test used was the independent samples t-test. The test was ideal since there
were only two groups to be compared.
3. What are the t value and p value for age? What do these results mean?
Answer
T-value -1.498
P-value 0.136
The results clearly shows that the differences in the means for the two groups (buzzy and
control) are insignificant at 5% level of significance.
4. What are the assumptions for conducting the independent samples t-test?
Answer
The assumptions are as follows:
a. Normal distribution of the datasets.
b. Dependent variable measured on ratio or interval level.
c. Homogeneity of variance in the two groups, that is, the two groups need to have
equal variance.
d. The groups should be independent of each other.
5. Are the groups in this study independent or dependent? Provide a rationale for your
answer.
Answer
The two groups are independent of each other. The groups are independent since a subject
being in buzzy group is not related at all with being in the control group.
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6. What is the null hypothesis for procedural self-reported pain measured with the Wong
Baker Faces Scale (WBFS) for the two groups? Was this null hypothesis accepted or
rejected in this study? Provide a rationale for your answer.
Answer
The null hypothesis;
Null hypothesis (H0): There is no significant difference in self-reported pain using the
WBFS.
The t-value is -6.498 and the p-value is 0.000 (a value greater than 5% level of
significance), thus the null hypothesis is rejected.
7. Should a Bonferroni procedure be conducted in this study? Provide a rationale for your
answer.
Answer
Bonferroni test (procedure) is not needed in this study since there are only two groups to
be compared. Bonferroni test is needed where there are three or more groups being
compared.
8. What variable has a result of t = −6.135, p = 0.000? What does the result mean?
Answer
The variable with the t-value being equal to −6.135 and p-value being equal to 0.000 is
Parent reported procedural child anxiety.
The result indicates there is significant statistical difference in the mean score for the
Parent reported procedural child anxiety between the two groups.
9. In your opinion, is it an expected or unexpected finding that both t values on Table 2 were
found to be statistically significant. Provide a rationale for your answer.
Answer
I expected both the t-values for the VAS and WBFS to be statistically significant. This is
based on the fact that the use of Buzzy occupied the mindset of the children from the real
IV insertion procedure and lessened their self-reported pain on two distinctive rating
scales for the pain.
10. Describe one potential clinical benefit for pediatric patients to receive the Buzzy
intervention that combined cold and vibration during IV insertion.
Answer
One noteworthy potential clinical advantage for pediatric patients to get the Buzzy
intervention is the decrease of pain and nervousness for the patient and it likewise makes
IV insertion less traumatizing for the young ones. Most kids fear needles and their dread
makes IV insertion much more difficult. This particular intervention could make the entire
treatment procedure less troublesome for both the patient and the physician administering.
(Grove 169-170)
Grove, Susan K., Daisha Cipher. Statistics for Nursing Research: A Workbook for Evidence-
Based Practice, 2nd Edition. Saunders, 022016. VitalBook file.
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Exercise 17
1. What are the assumptions for conducting a paired or dependent samples t-test in a study?
Which of these assumptions do you think were met by the Lindseth et al. (2014) study?
Answer
The assumptions are as follows:
a. Normal distribution of the datasets.
b. Dependent variable measured on ratio or interval level.
c. Homogeneity of variance in the two groups, that is, the two groups need to have equal
variance.
d. The groups should be independent of each other.
All the four assumptions were met
2. In the introduction, Lindseth et al. (2014) described a “2-week washout between diets.” What
does this mean? Why is this important?
Answer
The 2-week washout implies this is a between-subjects think about outline, and the agent
made the members (subjects) hold up about fourteen days before changing groups so as to
"washout" any influence of the high or low aspartame count calories. This was fundamental
since it keeps any bewildering influence of having similar subjects in two diverse trial
groups.
3. What is the paired t-test value for mood (irritability) between the participants' consumption
of high- versus low-aspartame diets? Is this result statistically significant? Provide a rationale
for your answer.
Answer
The computed t-test value for the mood (irritability) is 3.4. The value shows a statistically
significant value for the test. This is based on the fact that the given t-test value is much
larger than the critical value, and the p = 0.002 is less than the 5% level of significance.
4. State the null hypothesis for mood (irritability) that was tested in this study. Was this
hypothesis accepted or rejected? Provide a rationale for your answer.
Answer
The tested null hypothesis was that aspartame has insignificant effect on the mood. The
hypothesis was rejected; based on the fact that the p-value was less than 5% level of
significance (p = 0.002).
5. Which t value in Table 2 represents the greatest relative or standardized difference between
the high- and low-aspartame diets? Is this t value statistically significant? Provide a rationale
for your answer.
Answer
The t-value for depression represents the greatest standardized difference between high- and
low-aspartame diets. It is statistically significant (t = 3.8, p = 0.001). The p-value is less than
the alpha level of 0.05. also looking at the t-value for this variable, it has the largest t-value
indicating that it has the greatest standardized difference.
6. Discuss why the larger t values are more likely to be statistically significant.
Answer
The t-value estimates the relative difference in regard to the variation of the sample
population. This in this way implies, the bigger the t-value, the more the difference between
sample populations.
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7. Discuss the meaning of the results regarding depression for this study. What is the clinical
importance of this result?
Answer
The results of this research shows that a high aspartame diet negatively affects the
depression. This is clinically essential since aspartame is a typical ingredient in drinks such
as sodas. This could be a reason that a few people may have some type of depression or have
a discouraged state of mind. Changes in a person's eating routine could help ease these
issues.
8. What is the smallest, paired t-test value in Table 2? Why do you think the smaller t values are
not statistically significant?
Answer
The smallest t-value is in the memory (t = 1.5). A small t-value is not statistically significant
since the difference in the two groups is not large enough that it could have some significant
impact on the data.
9. Discuss the clinical importance of these study results about the consumption of aspartame.
Document your answer with a relevant source.
Answer
The results of this study are clinically important based on the fact that aspartame is very
much prevalent in the diets taken by a number of people. The fact that this artificial
sweetener has some sought of neurobehavioral effects should be a great call for alarm.
According to the link given here, aspartame can be very dangerous among the people
suffering from phenylketonuria in the sense that it can lead to diabetes, cancer, tardive
dyskinesia among other diseases.
10. Are these study findings related to the consumption of high- and low-aspartame diets ready
for implementation in practice? Provide a rationale for your answer.
Answer
This study is not at all ready for implementation in practice. This is based on the fact that
only 28 individuals were studied studied-making it difficult to make generalizations. The
sample size should definitely be large enough (more people should be studied) if the results
were to be generalized and the information was to be used in practice.
(Grove 177-178)
Grove, Susan K., Daisha Cipher. Statistics for Nursing Research: A Workbook for Evidence-
Based Practice, 2nd Edition. Saunders, 022016. VitalBook file.
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