Finding the Fourth Proportional to 21,180.56, 29,225.12 and 12,108.78

Step by Step Solution

1. Step 1: Write the proportion equation
   21,180.56 : 29,225.12 = 12,108.78 : x
2. Step 2: Convert to fraction form
   21,180.56/29,225.12 = 12,108.78/x
3. Step 3: Cross multiply
   21,180.56x = 29,225.12 × 12,108.78
4. Step 4: Simplify right side
   21,180.56x = 353,880,488.01
5. Step 5: Solve for x
   x = 353,880,488.01/21,180.56
6. Step 6: Final answer
   x = 16,707.80