The general formula to find the midpoint of a line in a 3D space is given by
[tex]M=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2},\frac{z_1+z_2}{2})[/tex]In this case, we have
[tex]M=(\frac{-13+0}{2},\frac{-4+4}{2},\frac{6+11}{2})=(\frac{-13}{2},0,\frac{17}{2})[/tex]So the position vector of the midpoint of the line PQ is
[tex]M=(-\frac{13}{2},0,\frac{17}{2})[/tex]which is option B.
