The Table Below Gives Data on Output for a Firm

The table below gives data on output for a firm in the short run.The firm is able to hire labor and its TPP is given.Compute the APP,MPP,and MRP for labor if the price of the good is fixed at $12 per unit.

$\begin{array}{cccc}\mathrm{LABOR} & \text { TPP }&APP&MPP&MRP \\1 & 4 &---&---&--- \\2 & 9&---&---&--- \\3 & 15 &---&---&--- \\4 & 21 &---&---&--- \\5 & 26 &---&---&--- \\6 & 30 &---&---&--- \\7 & 33 &---&---&--- \\8 & 35 &---&---&--- \\9 & 36 &---&---&--- \\\end{array}$