For this one-factor ANOVA (some information is missing), how many treatment groups were there? $$\begin{array} { l c c c c }
\hline \text { Source } & \text { Sum of Squares } & d f & \text { Mean Square } & F \
\hline \text { Treatment } & 654 && 218 & \
\text { Error } & 3,456 && 128 \
\hline \text { Total } & 4,110 & \
\hline
\end{array}$$
A)Cannot be determined
B)3
C)4
D)2

Question

For this one-factor ANOVA (some information is missing), how many treatment groups were there? $$\begin{array} { l c c c c } 
\hline \text { Source } & \text { Sum of Squares } & d f & \text { Mean Square } & F \
\hline \text { Treatment } & 654 && 218 & \
\text { Error } & 3,456 && 128 \
\hline \text { Total } & 4,110 & \
\hline
\end{array}$$
A)Cannot be determined
B)3
C)4
D)2

Quizplus · Accepted Answer

The degrees of freedom for treatment is calculated as the number of groups minus one. Given that the mean square for treatment is 218, dividing the sum of squares for treatment (654) by the mean square (218) gives 3, indicating there are 4 treatment groups (3+1).

For This One-Factor ANOVA (Some Information Is Missing), How Many