Finding the Fourth Proportional to 13,321.92, 18,380.88 and 7,729.68

Step by Step Solution

1. Step 1: Write the proportion equation
   13,321.92 : 18,380.88 = 7,729.68 : x
2. Step 2: Convert to fraction form
   13,321.92/18,380.88 = 7,729.68/x
3. Step 3: Cross multiply
   13,321.92x = 18,380.88 × 7,729.68
4. Step 4: Simplify right side
   13,321.92x = 142,078,320.52
5. Step 5: Solve for x
   x = 142,078,320.52/13,321.92
6. Step 6: Final answer
   x = 10,665.00