Finding the Fourth Proportional to 31,003.76, 42,785.61 and 16,856.57

Step by Step Solution

1. Step 1: Write the proportion equation
   31,003.76 : 42,785.61 = 16,856.57 : x
2. Step 2: Convert to fraction form
   31,003.76/42,785.61 = 16,856.57/x
3. Step 3: Cross multiply
   31,003.76x = 42,785.61 × 16,856.57
4. Step 4: Simplify right side
   31,003.76x = 721,218,629.96
5. Step 5: Solve for x
   x = 721,218,629.96/31,003.76
6. Step 6: Final answer
   x = 23,262.30