Finding the Fourth Proportional to 10,440.78, 14,408.40 and 5,725.10

Step by Step Solution

1. Step 1: Write the proportion equation
   10,440.78 : 14,408.40 = 5,725.10 : x
2. Step 2: Convert to fraction form
   10,440.78/14,408.40 = 5,725.10/x
3. Step 3: Cross multiply
   10,440.78x = 14,408.40 × 5,725.10
4. Step 4: Simplify right side
   10,440.78x = 82,489,458.80
5. Step 5: Solve for x
   x = 82,489,458.80/10,440.78
6. Step 6: Final answer
   x = 7,900.70