Finding the Fourth Proportional to 3,426.31, 5,140.09 and 1,086.90

Step by Step Solution

1. Step 1: Write the proportion equation
   3,426.31 : 5,140.09 = 1,086.90 : x
2. Step 2: Convert to fraction form
   3,426.31/5,140.09 = 1,086.90/x
3. Step 3: Cross multiply
   3,426.31x = 5,140.09 × 1,086.90
4. Step 4: Simplify right side
   3,426.31x = 5,586,763.82
5. Step 5: Solve for x
   x = 5,586,763.82/3,426.31
6. Step 6: Final answer
   x = 1,630.55