Finding the Fourth Proportional to 1,223.91, 1,688.79 and 726.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.91 : 1,688.79 = 726.42 : x
2. Step 2: Convert to fraction form
   1,223.91/1,688.79 = 726.42/x
3. Step 3: Cross multiply
   1,223.91x = 1,688.79 × 726.42
4. Step 4: Simplify right side
   1,223.91x = 1,226,770.83
5. Step 5: Solve for x
   x = 1,226,770.83/1,223.91
6. Step 6: Final answer
   x = 1,002.34