Participants rated their mood score out of 20 before and after listening to Reign in Blood by the thrash metal band Slayer. $\begin{array} { | c | c | }
\hline \text { Before Listening to Slayer } & \text { After Listening to } \mathbf { S l a y e r } \
\hline 5 & 14 \
\hline \mathbf { 8 } & \mathbf { 5 } \
\hline \mathbf { 9 } & 17 \
\hline 4 & 18 \
\hline \mathbf { 3 } & \mathbf { 8 } \
\hline 15 & 19 \
\hline 12 & 14 \
\hline \mathbf { 6 } & 16 \
\hline
\end{array}$
-What are the degrees of freedom for this study?

Question

Participants rated their mood score out of 20 before and after listening to Reign in Blood by the thrash metal band Slayer. $\begin{array} { | c | c | } 
\hline \text { Before Listening to Slayer } & \text { After Listening to } \mathbf { S l a y e r } \
\hline 5 & 14 \
\hline \mathbf { 8 } & \mathbf { 5 } \
\hline \mathbf { 9 } & 17 \
\hline 4 & 18 \
\hline \mathbf { 3 } & \mathbf { 8 } \
\hline 15 & 19 \
\hline 12 & 14 \
\hline \mathbf { 6 } & 16 \
\hline
\end{array}$ 
-What are the degrees of freedom for this study?

Quizplus · Accepted Answer

The degrees of freedom for a paired-samples t-test is n-1, where n is the number of pairs of scores. In this case, there are 8 pairs of scores, so the degrees of freedom is 8-1 = 7.

Participants Rated Their Mood Score Out of 20 Before and After