Using the basic force-equilibrium equations in the x and y directions, the forces F_A and F_B can be determined:

     ΣF_x = 0
     ΣF_y = 0

Sum the forces in both directions gives:

     -F_A cosα + F_B cosθ = 0
     F_A sinα + F_B sinθ - W = 0

Substitute numerical values up to four significant digits into the previous two equations.

     -F_A cos17.49 + F_B cos11.46 = 0
      F_A sin17.49 + F_B sin11.46 -146.7 = 0

Solve the two equations for the unknown values of F_A and F_B:

     
     F_A   = 488.1 - 0.6434 F_A

     F_A   = 297.0 lb
     F_B   = 289.0 lb

Round the given numerical values to two significant digits and substitute into previous equations.

     -F_A cos17 + F_B cos11 = 0
     F_A sin17 + F_B sin11 - 150 = 0

Solve the two equations for the unknown values of F_A and F_B:

The numerical values in each step are also rounded to two significant digits:

     
     F_A   = 520 - 0.64 F_A

     F_A   = 320 lb
     F_B   = 320 lb

Notice the value of F_A is 23 lb, or 7.7% higher, than when four significant digits were used. The percentage of error will vary from problem to problem, but when only two significant digits are used, the answer will generally be off by more than 1 percent. Therefore, rounding to only two significant digits should be avoided.