In a study designed to test the effectiveness of magnets for treating back pain,
ID: 3323868 • Letter: I
Question
In a study designed to test the effectiveness of magnets for treating back pain,35patients were given a treatment with magnets and also a sham treatment without magnets. Pain was measured using a scale from 0 (no pain) to 100 (extreme pain). After given the magnet treatments, the 35patients had pain scores with a mean of 10.0and a standard deviation of 2.6. After being given the sham treatments, the 35patients had pain scores with a mean of 98.1 and a standard deviation of 2.2 Complete parts (a) through (c) below. a) ___
Explanation / Answer
Solution:
Given that Z/2 = 1.96 at 95% confidence.
n = 35
x = 10.0
sd = 2.6
margin of error, E = (sd*Z/2)/sqrt(n) = (2.6*1.96)/sqrt(35) = 0.861
95% Confidence Interval = (x- E , x+ E)
= (10.0 - 0.861 , 10.0 + 0.861)
= (9.139 , 10.861)