First, I need the reactions at the supports (no need to draw the free body for this simple loading):
Taking the usual very short free body diagrams on either end, I get a shear of 48 kips at A and - 42 kips at C. The moments are zero at the ends. These will serve as checks on the values obtained using the singularity functions:
The singularity function is the constant C of integration, as is VA. I determined that it should be negative because concentrated forces drive the shear curve in the same direction - in the negative direction. A plot of the shear is:
So the maximum shear is 48 kips. You can see from the areas (in parentheses) that the moment reaches a maximum at 9 ft; it is 320.6 kip-ft.
From Appendix C,
| designation | Sx |
| W14 x 145 | 232 |
| W18 x 106 | 204 |
| W24 x 104 | 258 |
| W27 x 84 | 213 |
| W30 x 99 | 269 |