Finding the Fourth Proportional to 1,223.10, 1,688.18 and 726.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.10 : 1,688.18 = 726.03 : x
2. Step 2: Convert to fraction form
   1,223.10/1,688.18 = 726.03/x
3. Step 3: Cross multiply
   1,223.10x = 1,688.18 × 726.03
4. Step 4: Simplify right side
   1,223.10x = 1,225,665.70
5. Step 5: Solve for x
   x = 1,225,665.70/1,223.10
6. Step 6: Final answer
   x = 1,002.10