Finding the Fourth Proportional to 9,404.48, 12,978.34 and 5,155.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,404.48 : 12,978.34 = 5,155.50 : x
2. Step 2: Convert to fraction form
   9,404.48/12,978.34 = 5,155.50/x
3. Step 3: Cross multiply
   9,404.48x = 12,978.34 × 5,155.50
4. Step 4: Simplify right side
   9,404.48x = 66,909,831.87
5. Step 5: Solve for x
   x = 66,909,831.87/9,404.48
6. Step 6: Final answer
   x = 7,114.68