Finding the Fourth Proportional to 139,151.87, 192,029.61 and 78,721.27

Step by Step Solution

1. Step 1: Write the proportion equation
   139,151.87 : 192,029.61 = 78,721.27 : x
2. Step 2: Convert to fraction form
   139,151.87/192,029.61 = 78,721.27/x
3. Step 3: Cross multiply
   139,151.87x = 192,029.61 × 78,721.27
4. Step 4: Simplify right side
   139,151.87x = 15,116,814,370.53
5. Step 5: Solve for x
   x = 15,116,814,370.53/139,151.87
6. Step 6: Final answer
   x = 108,635.36