ADVANCED MATHIn three dimensions, the location of a point can be represented by the ordered triple (x, y, z). a) Find the coordinates of the midpoint of the line segment with endpoints A(2, 3, 1) and B(6, 7, 5). b) Write an expression for the coordinates of the midpoint of the line segment with endpoints $\left( x _ { 1 } , y _ { 1 } , z _ { 1 } \right)$ and $\left( x _ { 2 } , y _ { 2 } , z _ { 2 } \right)$