Finding the Fourth Proportional to 1,856.70, 2,783.25 and 686.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,856.70 : 2,783.25 = 686.37 : x
2. Step 2: Convert to fraction form
   1,856.70/2,783.25 = 686.37/x
3. Step 3: Cross multiply
   1,856.70x = 2,783.25 × 686.37
4. Step 4: Simplify right side
   1,856.70x = 1,910,339.30
5. Step 5: Solve for x
   x = 1,910,339.30/1,856.70
6. Step 6: Final answer
   x = 1,028.89