Finding the Fourth Proportional to 21,087.08, 29,099.94 and 12,139.82

Step by Step Solution

1. Step 1: Write the proportion equation
   21,087.08 : 29,099.94 = 12,139.82 : x
2. Step 2: Convert to fraction form
   21,087.08/29,099.94 = 12,139.82/x
3. Step 3: Cross multiply
   21,087.08x = 29,099.94 × 12,139.82
4. Step 4: Simplify right side
   21,087.08x = 353,268,033.61
5. Step 5: Solve for x
   x = 353,268,033.61/21,087.08
6. Step 6: Final answer
   x = 16,752.82