Finding the Fourth Proportional to 1,856.39, 2,783.71 and 686.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,856.39 : 2,783.71 = 686.34 : x
2. Step 2: Convert to fraction form
   1,856.39/2,783.71 = 686.34/x
3. Step 3: Cross multiply
   1,856.39x = 2,783.71 × 686.34
4. Step 4: Simplify right side
   1,856.39x = 1,910,568.09
5. Step 5: Solve for x
   x = 1,910,568.09/1,856.39
6. Step 6: Final answer
   x = 1,029.19