Final answer:
To determine the reaction RB, use the principle of equilibrium by summing the horizontal forces to zero and solving for RB.
Step-by-step explanation:
To determine the reaction RB, we need to apply the principle of equilibrium. The sum of the horizontal forces must be zero, so we have the equation RA + RB = F1 + F2 + F3. Substituting the given values, we get RA + RB = 15.25 + 26.50 + 32.75. Rearranging the equation, we find that RB = 15.25 + 26.50 + 32.75 - RA.