Finding the Fourth Proportional to 21,657.72, 29,887.82 and 12,705.37

Step by Step Solution

1. Step 1: Write the proportion equation
   21,657.72 : 29,887.82 = 12,705.37 : x
2. Step 2: Convert to fraction form
   21,657.72/29,887.82 = 12,705.37/x
3. Step 3: Cross multiply
   21,657.72x = 29,887.82 × 12,705.37
4. Step 4: Simplify right side
   21,657.72x = 379,735,811.59
5. Step 5: Solve for x
   x = 379,735,811.59/21,657.72
6. Step 6: Final answer
   x = 17,533.51