Finding the Fourth Proportional to 1,856.56, 2,785.92 and 687.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,856.56 : 2,785.92 = 687.39 : x
2. Step 2: Convert to fraction form
   1,856.56/2,785.92 = 687.39/x
3. Step 3: Cross multiply
   1,856.56x = 2,785.92 × 687.39
4. Step 4: Simplify right side
   1,856.56x = 1,915,013.55
5. Step 5: Solve for x
   x = 1,915,013.55/1,856.56
6. Step 6: Final answer
   x = 1,031.48