Finding the Fourth Proportional to 21,940.47, 30,263.67 and 12,981.69

Step by Step Solution

1. Step 1: Write the proportion equation
   21,940.47 : 30,263.67 = 12,981.69 : x
2. Step 2: Convert to fraction form
   21,940.47/30,263.67 = 12,981.69/x
3. Step 3: Cross multiply
   21,940.47x = 30,263.67 × 12,981.69
4. Step 4: Simplify right side
   21,940.47x = 392,873,582.20
5. Step 5: Solve for x
   x = 392,873,582.20/21,940.47
6. Step 6: Final answer
   x = 17,906.34