Here are the answers:
S (-1,2)
RS = sqrt(34)
XZ = 2 sqrt(34)
slope of RS = -3/5
slope of XZ = -3/5
the length of the segment that joins the midpoints of the two sides of the triangle is 1/2 the length of the third side
a segment that joins the midpoints of the two sides of the triangle is called a mid-segment