Finding the Fourth Proportional to 10,411.62, 15,599.88 and 5,139.60

Step by Step Solution

1. Step 1: Write the proportion equation
   10,411.62 : 15,599.88 = 5,139.60 : x
2. Step 2: Convert to fraction form
   10,411.62/15,599.88 = 5,139.60/x
3. Step 3: Cross multiply
   10,411.62x = 15,599.88 × 5,139.60
4. Step 4: Simplify right side
   10,411.62x = 80,177,143.25
5. Step 5: Solve for x
   x = 80,177,143.25/10,411.62
6. Step 6: Final answer
   x = 7,700.74