This is much easier when you use a software like MS Excel. You have to list the points first. These are: (1,3), (2,2.5), (3,4), (4,5), (5,6.5), (6,5.5), (7,7), (8,6), (9,7.5), (10,7) and (11,9).
Do a scatter plot for this points and add a trend line and you obtain the equation of the line fit. The equation is p=0.6m+2.4
We use this equation to find p when m=12. p = (0.6×12)+2.4 p = 9.6
