Finding the Fourth Proportional to 21,117.72, 29,141.46 and 12,165.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,117.72 : 29,141.46 = 12,165.48 : x
2. Step 2: Convert to fraction form
   21,117.72/29,141.46 = 12,165.48/x
3. Step 3: Cross multiply
   21,117.72x = 29,141.46 × 12,165.48
4. Step 4: Simplify right side
   21,117.72x = 354,519,848.80
5. Step 5: Solve for x
   x = 354,519,848.80/21,117.72
6. Step 6: Final answer
   x = 16,787.79