In the article "Sleep Apnea in Adults With Traumatic Brain Injury: A Preliminary Investigation" (Archives of Physical Medicine and Rehabilitation, Vol. 82, Issue 3, pp. 316321), J. Webster et al, investigated sleep-related breathing disorders in adults with traumatic brain injuries (TBI). The respiratory disturbance index (RDI), which is the number of apneic and hypopneic episodes per hour of sleep, was used as a measure of severity of sleep apnea. An RDI of 5 or more indicates sleep-related breathing disturbances. The RDIs for the females and males in the study are as follows.

Use the technology of your choice to answer the following questions. Explain your answers.

a. If you had to choose between the use of pooledt-procedures and nonpooled t-procedures here, which would you choose?

b. Is it reasonable to use the type of procedure that you selected in part (a)?

Short Answer

Expert verified

(a) the non-pooled t-procedure is utilised.

(b) It is not reasonable to use non pooled t-procedure.

Step by step solution

01

Part (a) Step 1: Given information  

Given in the question that, In the article "Sleep Apnea in Adults With Traumatic Brain Injury: A Preliminary Investigation" (Archives of Physical Medicine and Rehabilitation, Vol. 82, Issue 3, pp. 316321), J. Webster et al, investigated sleep-related breathing disorders in adults with traumatic brain injuries (TBI). The respiratory disturbance index (RDI), which is the number of apneic and hypopneic episodes per hour of sleep, was used as a measure of severity of sleep apnea. An RDI of 5 or more indicates sleep-related breathing disturbances. The RDIs for the females and males in the study are as follows.

we need to find that which one we choose pooled t-procedures or nonpooled t-procedures.

02

Part (a) Step 2: Explanation

Consider the table,

Population 1
Female
Population 2
Male

x¯1=0.943

x¯2=6.97

s1=0.947

s2=8.90

n1=7

n2=21

Because the two sample standard deviations from two populations are significantly different and sample sizes are unequal, the non-pooled t-procedure is utilised.

03

Part (b) Step 1: Given information  

Given in the question that, In the article "Sleep Apnea in Adults With Traumatic Brain Injury: A Preliminary Investigation" (Archives of Physical Medicine and Rehabilitation, Vol. 82, Issue 3, pp. 316321), J. Webster et al, investigated sleep-related breathing disorders in adults with traumatic brain injuries (TBI). The respiratory disturbance index (RDI), which is the number of apneic and hypopneic episodes per hour of sleep, was used as a measure of severity of sleep apnea. An RDI of 5 or more indicates sleep-related breathing disturbances. The RDIs for the females and males in the study are as follows.

we need to verify that whether it is reasonable to use the type of procedure that you selected in part (a)

04

Part (b) Step 2: Explanation

The graph for the above are shown below,

and

In light of the foregoing normal plots, it is not appropriate to employ the non pooledt-procedure because the normal plot for male data indicates the presence of outliers. As a result, the male population is out of the ordinary.

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Most popular questions from this chapter

Cooling Down. Cooling down with a cold drink before exercise in the heat is believed to help an athlete perform. Researcher 1. Dugas explored the difference between cooling down with an ice slurry (slushy) and with cold water in the article "lce Slurry Ingestion Increases Running Time in the Heat" (Clinical Journal of Sports Medicine, Vol. 21, No, 6, pp. 541-542). Ten male participants drank a flavored ice slurry and ran on a treadmill in a controlled hot and humid environment. Days later, the same participants drank cold water and ran on a treadmill in the same bot and humid environment. The following table shows the times, in minutes, it took to fatigue on the treadmill for both the ice slurry and the cold water.

At the 1%significance level, do the data provide sufficient evidence to conclude that, on average, cold water is less effective than ice slurry For optimizing athletic performance in the heat? (Note; The mean and standard deviation of the paired differences are -5.9minutes and 1.60minutes, respectively.)

In Exercise 10.83, you conducted a nonpooled t-test to decide whether the mean number of acute postoperative days spent in the hospital is smaller with the dynamic system than with the static system. Use the technology of your choice to perform the following tasks.

a. Using a pooledt-test, repeat that hypothesis test.

b. Compare your results from the pooled and nonpooled t-tests.

c. Which test do you think is more appropriate, the pooled or nonpooled t-test? Explain your answer.

Give an example of interest to you for comparing two population means. Identify the variable under consideration and the two populations.

A hypothesis test is to be performed to compare the means of two populations, using a paired sample. The sample of 15 paired differences contains an outlier but otherwise is roughly bell-shaped. Assuming that it is not legitimate to remove the outlier, which test is better to use-the paired t-test or the paired Wilcoxon signed-rank test? Explain your answer,

Political Prisoners. According to the American Psychiatric Association, posttraumatic stress disorder (PTSD) is a common psychological consequence of traumatic events that involve a threat to life or physical integrity. During the Cold War, some 200,000 people in East Germany were imprisoned for political reasons. Many were subjected to physical and psychological torture during their imprisonment, resulting in PTSD. A. Ehlers et al. studied various characteristics of political prisoners from the former East Germany and presented their findings in the paper "Posttraumatic Stress Dis-order (PTSD) Following Political Imprisonment: The Role of Mental Defeat, Alienation, and Perceived Permanent Change" (Journal of Abnormal Psychology, Vol. 109, pp. 45-55). The researchers randomly and independently selected 32 former prisoners diagnosed with chronic PTSD and 20 former prisoners that were diagnosed with PTSD after release from prison but had since recovered (remitted). The ages, in years, at arrest yielded the following summary statistics.

At the 10% significance level, is there sufficient evidence to conclude that a difference exists in the mean age at arrest of East German prisoners with chronic PTSD and remitted PTSD?

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