Finding the Fourth Proportional to 21,560.55, 29,752.41 and 12,128.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,560.55 : 29,752.41 = 12,128.50 : x
2. Step 2: Convert to fraction form
   21,560.55/29,752.41 = 12,128.50/x
3. Step 3: Cross multiply
   21,560.55x = 29,752.41 × 12,128.50
4. Step 4: Simplify right side
   21,560.55x = 360,852,104.69
5. Step 5: Solve for x
   x = 360,852,104.69/21,560.55
6. Step 6: Final answer
   x = 16,736.68