Finding the Fourth Proportional to 12,390.57, 18,589.29 and 5,729.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390.57 : 18,589.29 = 5,729.10 : x
2. Step 2: Convert to fraction form
   12,390.57/18,589.29 = 5,729.10/x
3. Step 3: Cross multiply
   12,390.57x = 18,589.29 × 5,729.10
4. Step 4: Simplify right side
   12,390.57x = 106,499,901.34
5. Step 5: Solve for x
   x = 106,499,901.34/12,390.57
6. Step 6: Final answer
   x = 8,595.24