Finding the Fourth Proportional to 21,943.98, 30,285.72 and 12,999.06

Step by Step Solution

1. Step 1: Write the proportion equation
   21,943.98 : 30,285.72 = 12,999.06 : x
2. Step 2: Convert to fraction form
   21,943.98/30,285.72 = 12,999.06/x
3. Step 3: Cross multiply
   21,943.98x = 30,285.72 × 12,999.06
4. Step 4: Simplify right side
   21,943.98x = 393,685,891.42
5. Step 5: Solve for x
   x = 393,685,891.42/21,943.98
6. Step 6: Final answer
   x = 17,940.50