Finding the Fourth Proportional to 22,446.38, 30,978.80 and 12,889.25

Step by Step Solution

1. Step 1: Write the proportion equation
   22,446.38 : 30,978.80 = 12,889.25 : x
2. Step 2: Convert to fraction form
   22,446.38/30,978.80 = 12,889.25/x
3. Step 3: Cross multiply
   22,446.38x = 30,978.80 × 12,889.25
4. Step 4: Simplify right side
   22,446.38x = 399,293,607.57
5. Step 5: Solve for x
   x = 399,293,607.57/22,446.38
6. Step 6: Final answer
   x = 17,788.78