Finding the Fourth Proportional to 21,890.25, 30,208.56 and 12,458.82

Step by Step Solution

1. Step 1: Write the proportion equation
   21,890.25 : 30,208.56 = 12,458.82 : x
2. Step 2: Convert to fraction form
   21,890.25/30,208.56 = 12,458.82/x
3. Step 3: Cross multiply
   21,890.25x = 30,208.56 × 12,458.82
4. Step 4: Simplify right side
   21,890.25x = 376,363,011.50
5. Step 5: Solve for x
   x = 376,363,011.50/21,890.25
6. Step 6: Final answer
   x = 17,193.18