Finding the Fourth Proportional to 21,656.76, 29,872.85 and 13,150.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,656.76 : 29,872.85 = 13,150.61 : x
2. Step 2: Convert to fraction form
   21,656.76/29,872.85 = 13,150.61/x
3. Step 3: Cross multiply
   21,656.76x = 29,872.85 × 13,150.61
4. Step 4: Simplify right side
   21,656.76x = 392,845,984.82
5. Step 5: Solve for x
   x = 392,845,984.82/21,656.76
6. Step 6: Final answer
   x = 18,139.65