- Information
- AI Chat
Week 2 discussion 2
Intro to Biomedical Statistics (BST 322)
National University (US)
Recommended for you
Preview text
Week Two, Discussion Two Question 2: The two sample t test on shingles patients
A pilot study was conducted to evaluate the effectiveness of pain alleviation in patients with facial shingles. 24 patients were randomly assigned to one of 2 treatment groups; rest vs. acupuncture. After two weeks of treatment, the subjects were then asked to rate their pain on a scale from 1 to 10 with 10 being the most pain they have ever experienced. The data they recorded is shown below: Rest Acupuncture 5 5 5 6 10 7 9 2 8 9 6 8 9 7 4 4 7 3 8 5 4 9 3 2
- State the null and alternative hypothesis.
Null hypothesis: There is no difference in the effectiveness of pain alleviation in patients with facial shingles using rest and/or acupuncture.
Alternative hypothesis: There is a difference in the effectiveness of pain alleviation in patients with facial shingles using rest and/or acupuncture.
- What is the value of t for the analysis?
Two sample T hypothesis test:
μ 1 : Mean of Rest μ 2 : Mean of Acupuncture μ 1 - μ 2 : Difference between two means H 0 : μ 1 - μ 2 = 0 HA : μ 1 - μ 2 ≠ 0 (with pooled variances)
Hypothesis test results: Difference Sample Diff. Std. Err. DF T-Stat P-value μ 1 - μ 2 0.916666670 22 0 0. T-Stat is 0.
Is this value significant and at what level? Why? The value is not significant because the P-value is greater than alpha significance level of 0. The T-stat is less than critical value of 2 which correlates to being not significant. These both agree with each other.
Why is a pooled variance test allowed here while a separate variance t test is not appropriate?
You would use a pooled variance test when variances of the two populations are equal. Separate variance T-tests are used when variances are unequal. The variances given are equal, so you would use the pooled variance test.
Week 2 discussion 2
Course: Intro to Biomedical Statistics (BST 322)
University: National University (US)
This is a preview
Access to all documents
Get Unlimited Downloads
Improve your grades
