Researchers conducted a study to determine whether magnets are effective in treating back pain. Pain was measured using the visual analog​ scale, and the results shown below are among the results obtained in the study. Higher scores correspond to greater pain levels. Assume that the two samples are independent simple random samples selected from normally distributed​ populations, and do not assume that the population standard deviations are equal. Complete parts​ (a) to​ (c) below

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Researchers conducted a study to determine whether magnets are effective in treating back pain. Pain was measured using the visual analog​ scale, and the results shown below are among the results obtained in the study. Higher scores correspond to greater pain levels. Assume that the two samples are independent simple random samples selected from normally distributed​ populations, and do not assume that the population standard deviations are equal. Complete parts​ (a) to​ (c) below.
 
Reduction in Pain Level After Magnet Treatment
​(μ1​):
n=16​,
x=0.41​,
s=0.93
Reduction in Pain Level After Sham Treatment
​(μ2​):
n=16​,
x=0.37​,
s=1.46
 
 
 

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Part 1
a. Use a
0.05
significance level to test the claim that those treated with magnets have a greater mean reduction in pain than those given a sham treatment​ (similar to a​ placebo).
 
What are the null and alternative​ hypotheses?
 
 
A.
H0​:
μ1<μ2
H1​:
μ1≥μ2
 
B.
H0​:
μ1≠μ2
H1​:
μ1<μ2
 
C.
H0​:
μ1=μ2
H1​:
μ1>μ2
 
D.
H0​:
μ1=μ2
H1​:
μ1≠μ2
Part 2
The test​ statistic, t, is
enter your response here.
​(Round to two decimal places as​ needed.)
Part 3
The​ P-value is
enter your response here.
​(Round to three decimal places as​ needed.)
Part 4
State the conclusion for the test.
 
 
Reject
Fail to reject
the null hypothesis. There
 
is not
is
sufficient evidence to support the claim that those treated with magnets have a greater mean reduction in pain than those given a sham treatment.
Part 5
b. Construct a confidence interval appropriate for the hypothesis test in part​ (a).
 
enter your response here<μ1−μ2<enter your response here
​(Round to two decimal places as​ needed.)
Part 6
c. Does it appear that magnets are effective in treating back​ pain? Is it valid to argue that magnets might appear to be effective if the sample sizes are​ larger? Choose the correct answer below.
 
 
A.
It appears that magnets
are
effective in treating back​ pain, because the confidence interval contains only positive values.
 
B.
It appears that magnets
are not
effective in treating back​ pain, because the​ P-value is
less
than the significance level.
 
C.
It appears that magnets
are not
effective in treating back​ pain, because 0
is
in the confidence interval.
 
D.
It appears that magnets
are
effective in treating back​ pain, because the​ P-value is
greater
than the significance level.
Part 7
Is it valid to argue that magnets might appear to be effective if the sample sizes are​ larger? Choose the correct answer below.
 
 
A.
​No, because the magnets already appear to be effective.
 
B.
​No, because increasing the sample size will increase the​ P-value.
 
C.
​Yes, because increasing the sample size will decrease the​ P-value.
 
D.
​Yes, because increasing the sample size will increase the effectiveness.
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