Finding the Fourth Proportional to 1,381.57, 2,069.58 and 686.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.57 : 2,069.58 = 686.14 : x
2. Step 2: Convert to fraction form
   1,381.57/2,069.58 = 686.14/x
3. Step 3: Cross multiply
   1,381.57x = 2,069.58 × 686.14
4. Step 4: Simplify right side
   1,381.57x = 1,420,019.02
5. Step 5: Solve for x
   x = 1,420,019.02/1,381.57
6. Step 6: Final answer
   x = 1,027.83