Answer
Final compound formed has the formula $K_{3}PO_{4}$.
Work Step by Step
The metal cation is $K^{+}$
The polyatomic anion is $PO_{4}^{3-}$
Combine 3 $K^{+}$ and 1 $PO_{4}^{3-}$ to balance the charge.
Final compound formed has the formula $K_{3}PO_{4}$.
