Finding the Fourth Proportional to 21,900, 30,222.05 and 12,468.56

Step by Step Solution

1. Step 1: Write the proportion equation
   21,900 : 30,222.05 = 12,468.56 : x
2. Step 2: Convert to fraction form
   21,900/30,222.05 = 12,468.56/x
3. Step 3: Cross multiply
   21,900x = 30,222.05 × 12,468.56
4. Step 4: Simplify right side
   21,900x = 376,825,456.96
5. Step 5: Solve for x
   x = 376,825,456.96/21,900
6. Step 6: Final answer
   x = 17,206.64