Finding the Fourth Proportional to 139,731.33, 192,828.66 and 78,469

Step by Step Solution

1. Step 1: Write the proportion equation
   139,731.33 : 192,828.66 = 78,469 : x
2. Step 2: Convert to fraction form
   139,731.33/192,828.66 = 78,469/x
3. Step 3: Cross multiply
   139,731.33x = 192,828.66 × 78,469
4. Step 4: Simplify right side
   139,731.33x = 15,131,072,121.54
5. Step 5: Solve for x
   x = 15,131,072,121.54/139,731.33
6. Step 6: Final answer
   x = 108,286.90