$\overline{MQ}$ and $\overline{NR}$ intersect at point $P$. $MP=PR$. If the measure of $\angle QPR$ is $(4x{)}^{\circ }$ and the measure of $\angle QMR$ is $(x+15{)}^{\circ }$, what is the measure, in degrees, of $\angle QMR$? (Disregard the degree symbol when gridding your answer.)