Consider an naca 2412 airfoil (the meaning of the number designations for standard naca airfoil shapes is discussed in chapter 4).
the following is a tabulation of the lift, drag, and moment coefficients about the quarter chord for this airfoil, as a function of angle of attack.

a (degrees) -2.0 2.0 4.0 c 0.05 0.25 0.44 0.64 0.85 1.08 1.26 1.43 1.56 cd 0.006 0.006 0.006 0.007 0.0075 0.0092 0.0115 0.0150 0.0186 cm. c/4 -0.042 -0.040 -0.038 -0.036 -0.036 -0.036 -0.034 -0.030 -0.025 6.0 8.0 10.0 12.0 14.0

(a) plot on graph paper the variation of xcp/c as a function of a.

(b) as angle of attack increase from -2 to 14 degree, where will the center of pressure approach?