Finding the Fourth Proportional to 16,978.58, 25,440.20 and 10,390.94

Step by Step Solution

1. Step 1: Write the proportion equation
   16,978.58 : 25,440.20 = 10,390.94 : x
2. Step 2: Convert to fraction form
   16,978.58/25,440.20 = 10,390.94/x
3. Step 3: Cross multiply
   16,978.58x = 25,440.20 × 10,390.94
4. Step 4: Simplify right side
   16,978.58x = 264,347,591.79
5. Step 5: Solve for x
   x = 264,347,591.79/16,978.58
6. Step 6: Final answer
   x = 15,569.48