Finding the Fourth Proportional to 21,411.54, 29,548.72 and 11,980.17

Step by Step Solution

1. Step 1: Write the proportion equation
   21,411.54 : 29,548.72 = 11,980.17 : x
2. Step 2: Convert to fraction form
   21,411.54/29,548.72 = 11,980.17/x
3. Step 3: Cross multiply
   21,411.54x = 29,548.72 × 11,980.17
4. Step 4: Simplify right side
   21,411.54x = 353,998,688.88
5. Step 5: Solve for x
   x = 353,998,688.88/21,411.54
6. Step 6: Final answer
   x = 16,533.08