Finding the Fourth Proportional to 22,072.64, 30,456.81 and 12,639.38

Step by Step Solution

1. Step 1: Write the proportion equation
   22,072.64 : 30,456.81 = 12,639.38 : x
2. Step 2: Convert to fraction form
   22,072.64/30,456.81 = 12,639.38/x
3. Step 3: Cross multiply
   22,072.64x = 30,456.81 × 12,639.38
4. Step 4: Simplify right side
   22,072.64x = 384,955,042.89
5. Step 5: Solve for x
   x = 384,955,042.89/22,072.64
6. Step 6: Final answer
   x = 17,440.38