Finding the Fourth Proportional to 139,340.81, 192,283.89 and 78,911.89

Step by Step Solution

1. Step 1: Write the proportion equation
   139,340.81 : 192,283.89 = 78,911.89 : x
2. Step 2: Convert to fraction form
   139,340.81/192,283.89 = 78,911.89/x
3. Step 3: Cross multiply
   139,340.81x = 192,283.89 × 78,911.89
4. Step 4: Simplify right side
   139,340.81x = 15,173,484,510.79
5. Step 5: Solve for x
   x = 15,173,484,510.79/139,340.81
6. Step 6: Final answer
   x = 108,894.76