Finding the Fourth Proportional to 10,661.37, 15,978.12 and 5,725.23

Step by Step Solution

1. Step 1: Write the proportion equation
   10,661.37 : 15,978.12 = 5,725.23 : x
2. Step 2: Convert to fraction form
   10,661.37/15,978.12 = 5,725.23/x
3. Step 3: Cross multiply
   10,661.37x = 15,978.12 × 5,725.23
4. Step 4: Simplify right side
   10,661.37x = 91,478,411.97
5. Step 5: Solve for x
   x = 91,478,411.97/10,661.37
6. Step 6: Final answer
   x = 8,580.36