Below Is a Partial Multiple Regression ANOVA Table -How Many Observations Were in the Sample

Short Answer

Below is a partial multiple regression ANOVA table.
$$\begin{array} { l l l } \text { Source } & \text { SS } & \text { df } \\\mathrm { X } _ { 1 } & 535.9569 & 1 \\\mathrm { X } _ { 2 } & 1,167.5634 & 1 \\\mathrm { X } _ { 3 } & 18.9886 & 1 \\\text { Error } & 3,459 .6803 & 8\end{array}$$
-How many observations were in the sample?