A solution is made by mixing $3\mathrm{.}3$ mL of $2\mathrm{.}0$ M K$2$HPO$4$ and $1\mathrm{.}9$ of $2\mathrm{.}0$ M KH$2$PO$4.$ The solution is diluted to a final volume of $200$ mL$.$ What is the pH of the final solution? pKa of potassium phosphate is $7\mathrm{.}2.$