Answer
Final compound formed has the formula $Ca_{3}(PO_{4})_{2}$.
Work Step by Step
The metal cation is $Ca^{2+}$
The polyatomic anion is $PO_{4}^{3-}$
Combine 3 $Ca^{2+}$ and 2 $PO_{4}^{3-}$ to balance the charge.
Final compound formed has the formula $Ca_{3}(PO_{4})_{2}$.