Finding the Fourth Proportional to 1,209.57, 1,812.69 and 689.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,209.57 : 1,812.69 = 689.82 : x
2. Step 2: Convert to fraction form
   1,209.57/1,812.69 = 689.82/x
3. Step 3: Cross multiply
   1,209.57x = 1,812.69 × 689.82
4. Step 4: Simplify right side
   1,209.57x = 1,250,429.82
5. Step 5: Solve for x
   x = 1,250,429.82/1,209.57
6. Step 6: Final answer
   x = 1,033.78