Finding the Fourth Proportional to 9,404.87, 12,978.02 and 5,155.25

Step by Step Solution

1. Step 1: Write the proportion equation
   9,404.87 : 12,978.02 = 5,155.25 : x
2. Step 2: Convert to fraction form
   9,404.87/12,978.02 = 5,155.25/x
3. Step 3: Cross multiply
   9,404.87x = 12,978.02 × 5,155.25
4. Step 4: Simplify right side
   9,404.87x = 66,904,846.94
5. Step 5: Solve for x
   x = 66,904,846.94/9,404.87
6. Step 6: Final answer
   x = 7,113.86