Finding the Fourth Proportional to 139,002.57, 191,821.46 and 78,571.09

Step by Step Solution

1. Step 1: Write the proportion equation
   139,002.57 : 191,821.46 = 78,571.09 : x
2. Step 2: Convert to fraction form
   139,002.57/191,821.46 = 78,571.09/x
3. Step 3: Cross multiply
   139,002.57x = 191,821.46 × 78,571.09
4. Step 4: Simplify right side
   139,002.57x = 15,071,620,914.47
5. Step 5: Solve for x
   x = 15,071,620,914.47/139,002.57
6. Step 6: Final answer
   x = 108,426.92