Finding the Fourth Proportional to 139,128.59, 191,997.45 and 78,697.94

Step by Step Solution

1. Step 1: Write the proportion equation
   139,128.59 : 191,997.45 = 78,697.94 : x
2. Step 2: Convert to fraction form
   139,128.59/191,997.45 = 78,697.94/x
3. Step 3: Cross multiply
   139,128.59x = 191,997.45 × 78,697.94
4. Step 4: Simplify right side
   139,128.59x = 15,109,803,800.25
5. Step 5: Solve for x
   x = 15,109,803,800.25/139,128.59
6. Step 6: Final answer
   x = 108,603.15