Finding the Fourth Proportional to 21,561.15, 29,753.92 and 12,000.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,561.15 : 29,753.92 = 12,000.61 : x
2. Step 2: Convert to fraction form
   21,561.15/29,753.92 = 12,000.61/x
3. Step 3: Cross multiply
   21,561.15x = 29,753.92 × 12,000.61
4. Step 4: Simplify right side
   21,561.15x = 357,065,189.89
5. Step 5: Solve for x
   x = 357,065,189.89/21,561.15
6. Step 6: Final answer
   x = 16,560.58