Pulling data from unusual table

I'm looking for a way pull a specific value from a matrix by specifying the Y value through a drop down menu and the X value by interpolating the temperature. See figures.  I can't figure out a way for Mathcad to use a value in one matrix to determine a value in a different matrix. Hopefully one of you have an idea. See the figures for the tables and what I have pulled into Mathcad from Excel.