Finding the Fourth Proportional to 139,304.50, 192,240.21 and 79,688.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,304.50 : 192,240.21 = 79,688.50 : x
2. Step 2: Convert to fraction form
   139,304.50/192,240.21 = 79,688.50/x
3. Step 3: Cross multiply
   139,304.50x = 192,240.21 × 79,688.50
4. Step 4: Simplify right side
   139,304.50x = 15,319,333,974.59
5. Step 5: Solve for x
   x = 15,319,333,974.59/139,304.50
6. Step 6: Final answer
   x = 109,970.13