/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 76 Use the following information to... [FREE SOLUTION] | 91Ó°ÊÓ

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Use the following information to answer the next five exercises. A doctor wants to know if a blood pressure medication is effective. Six subjects have their blood pressures recorded. After twelve weeks on the medication, the same six subjects have their blood pressure recorded again. For this test, only systolic pressure is of concern. Test at the 1% significance level. $$ \begin{array}{|l|l|l|l|l|l|}\hline \text { Patient } & {\mathbf{A}} & {\mathbf{B}} & {\mathbf{C}} & {\mathbf{D}} & {\mathbf{E}} & {\mathbf{F}} \\\ \hline \text { Before } & {161} & {162} & {165} & {162} & {166} & {171} \\\ \hline \text { After } & {158} & {159} & {166} & {160} & {167} & {169} \\\ \hline\end{array} $$ What is the sample mean difference?

Short Answer

Expert verified
The sample mean difference is 1.33.

Step by step solution

01

Identify Differences

Calculate the difference in systolic blood pressure for each subject by subtracting the 'After' measurement from the 'Before' measurement. For each patient, do the following: - Patient A: 161 - 158 = 3 - Patient B: 162 - 159 = 3 - Patient C: 165 - 166 = -1 - Patient D: 162 - 160 = 2 - Patient E: 166 - 167 = -1 - Patient F: 171 - 169 = 2.
02

Sum the Differences

Add together all the differences calculated in Step 1 to find the total difference. Total difference = 3 + 3 - 1 + 2 - 1 + 2 = 8.
03

Calculate the Sample Mean Difference

Divide the total difference by the number of subjects (6) to find the sample mean difference. Sample mean difference = Total difference / Number of subjects = 8 / 6 = 1.33.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Blood Pressure Medication Effectiveness
Effectiveness of blood pressure medication is about how well the medicine works to reduce high blood pressure, specifically focusing on systolic blood pressure in this context. Systolic blood pressure is the top number in a blood pressure reading, and it indicates how much pressure your blood is exerting against your artery walls when the heart beats.
In medical studies, like our exercise, effectiveness is often measured by comparing patient conditions before and after taking the medication. Here, six patients had their blood pressures recorded before starting the medication and again after twelve weeks of treatment.
Lower systolic readings after taking medication would typically suggest effectiveness, implying that the medication is helping reduce high blood pressure.
Systolic Blood Pressure
Systolic blood pressure is a crucial part of assessing heart health. It is the reading you get when the heart is contracting and pushing blood through the arteries. For this exercise, we're interested in how it changes when patients are on medication.
This value is essential because sustained high systolic pressure can lead to serious health complications, such as heart attacks and strokes. By focusing on this number, the exercise aims to understand whether the blood pressure medication sufficiently lowers this pressure, reflecting its effectiveness. Patients' before and after readings are compared to check for reduction, which is an indicator of improvement in health status.
Hypothesis Testing
Hypothesis testing is a statistical method used to make decisions about the effectiveness of a treatment or intervention, like medication. It involves comparing data against a hypothesis (an initial claim).
In this exercise, the doctor wants to test if the blood pressure medication is effective. The hypothesis could be framed as:\[ H_0: \text{There is no difference in blood pressure before and after medication.} \]
\[ H_1: \text{The medication effectively lowers blood pressure.} \]
Through statistical tests, we decide to reject or not reject the null hypothesis \( H_0 \). The decision is based on the changes in systolic blood pressure over time among the subjects. If the medication significantly reduces blood pressure, we reject \( H_0 \) in favor of \( H_1 \).
Significance Level
The significance level, denoted as \( \alpha \), is the threshold set for making decisions in hypothesis testing. It's used to determine how much evidence we need to reject the null hypothesis. A common choice is 5% (0.05), but in this exercise, a more stringent level of 1% (0.01) is used.
The 1% significance level indicates that there is a very low probability of concluding the medication is effective when it's not. This means greater rigor is applied, reducing the chance of false positives. However, obtaining enough statistical evidence to prove effectiveness becomes harder, as a smaller margin of error is allowed for unexpected results.
Thus, using a 1% significance level emphasizes the doctor's concern about drawing accurate conclusions regarding the medication's effectiveness on systolic blood pressure.

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Most popular questions from this chapter

We are interested in whether children’s educational computer software costs less, on average, than children’s entertainment software. Thirty-six educational software titles were randomly picked from a catalog. The mean cost was \(31.14 with a standard deviation of \)4.69. Thirty-five entertainment software titles were randomly picked from the same catalog. The mean cost was \(33.86 with a standard deviation of \)10.87. Decide whether children’s educational software costs less, on average, than children’s entertainment software.

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