Finding the Fourth Proportional to 21,989.88, 30,346.25 and 12,558.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,989.88 : 30,346.25 = 12,558.38 : x
2. Step 2: Convert to fraction form
   21,989.88/30,346.25 = 12,558.38/x
3. Step 3: Cross multiply
   21,989.88x = 30,346.25 × 12,558.38
4. Step 4: Simplify right side
   21,989.88x = 381,099,524.55
5. Step 5: Solve for x
   x = 381,099,524.55/21,989.88
6. Step 6: Final answer
   x = 17,330.68