A researcher would like to evaluate the effectiveness of a pain-relief patch designed for lower back pain.Prior to testing the patch,each of n = 8 patients rates the current level of back pain on a scale from 1 to 10.After wearing the patch for 90 minutes,a second pain rating is recorded.The data are as follows:
$$\begin{array} { r c }
\text { Before } & \text { After } \
\hline 6 & 2 \
8 & 3 \
9 & 4 \
8 & 1 \
10 & 2 \
5 & 3 \
9 & 8 \
7 & 7
\end{array}$$
a.Compute the mean and variance for the sample of difference scores.
b.Do the results indicate a significant difference? Use a two-tailed test with α = .05
c.Compute Cohen's d to measure the size of the effect.

Question

A researcher would like to evaluate the effectiveness of a pain-relief patch designed for lower back pain.Prior to testing the patch,each of n = 8 patients rates the current level of back pain on a scale from 1 to 10.After wearing the patch for 90 minutes,a second pain rating is recorded.The data are as follows:
 $$\begin{array} { r c } 
\text { Before } & \text { After } \
\hline 6 & 2 \
8 & 3 \
9 & 4 \
8 & 1 \
10 & 2 \
5 & 3 \
9 & 8 \
7 & 7
\end{array}$$ 
a.Compute the mean and variance for the sample of difference scores.
b.Do the results indicate a significant difference? Use a two-tailed test with α = .05
c.Compute Cohen's d to measure the size of the effect.

Quizplus · Accepted Answer

The Answer of A researcher would like to evaluate the effectiveness of a pain-relief patch designed for lower back pain.Prior to testing the patch,each of n = 8 patients rates the current level of back pain on a scale from 1 to 10.After wearing the patch for 90 minutes,a second pain rating is recorded.The data are as follows:
 $$\begin{array} { r c } 
\text { Before } & \text { After } \
\hline 6 & 2 \
8 & 3 \
9 & 4 \
8 & 1 \
10 & 2 \
5 & 3 \
9 & 8 \
7 & 7
\end{array}$$ 
a.Compute the mean and variance for the sample of difference scores.
b.Do the results indicate a significant difference? Use a two-tailed test with α = .05
c.Compute Cohen's d to measure the size of the effect.

A Researcher Would Like to Evaluate the Effectiveness of a Pain-Relief