Finding the Fourth Proportional to 139,906.72, 193,049.22 and 78,640.84

Step by Step Solution

1. Step 1: Write the proportion equation
   139,906.72 : 193,049.22 = 78,640.84 : x
2. Step 2: Convert to fraction form
   139,906.72/193,049.22 = 78,640.84/x
3. Step 3: Cross multiply
   139,906.72x = 193,049.22 × 78,640.84
4. Step 4: Simplify right side
   139,906.72x = 15,181,552,822.14
5. Step 5: Solve for x
   x = 15,181,552,822.14/139,906.72
6. Step 6: Final answer
   x = 108,511.96