Finding the Fourth Proportional to 139,059.38, 191,905.99 and 78,628.71

Step by Step Solution

1. Step 1: Write the proportion equation
   139,059.38 : 191,905.99 = 78,628.71 : x
2. Step 2: Convert to fraction form
   139,059.38/191,905.99 = 78,628.71/x
3. Step 3: Cross multiply
   139,059.38x = 191,905.99 × 78,628.71
4. Step 4: Simplify right side
   139,059.38x = 15,089,320,320.86
5. Step 5: Solve for x
   x = 15,089,320,320.86/139,059.38
6. Step 6: Final answer
   x = 108,509.90