Finding the Fourth Proportional to 139,116.89, 191,981.26 and 78,686.24

Step by Step Solution

1. Step 1: Write the proportion equation
   139,116.89 : 191,981.26 = 78,686.24 : x
2. Step 2: Convert to fraction form
   139,116.89/191,981.26 = 78,686.24/x
3. Step 3: Cross multiply
   139,116.89x = 191,981.26 × 78,686.24
4. Step 4: Simplify right side
   139,116.89x = 15,106,282,859.62
5. Step 5: Solve for x
   x = 15,106,282,859.62/139,116.89
6. Step 6: Final answer
   x = 108,586.98