Finding the Fourth Proportional to 100,724.91, 139,003.76 and 55,404.80

Step by Step Solution

1. Step 1: Write the proportion equation
   100,724.91 : 139,003.76 = 55,404.80 : x
2. Step 2: Convert to fraction form
   100,724.91/139,003.76 = 55,404.80/x
3. Step 3: Cross multiply
   100,724.91x = 139,003.76 × 55,404.80
4. Step 4: Simplify right side
   100,724.91x = 7,701,475,522.05
5. Step 5: Solve for x
   x = 7,701,475,522.05/100,724.91
6. Step 6: Final answer
   x = 76,460.49