Finding the Fourth Proportional to 139,396.98, 192,371.94 and 78,976.20

Step by Step Solution

1. Step 1: Write the proportion equation
   139,396.98 : 192,371.94 = 78,976.20 : x
2. Step 2: Convert to fraction form
   139,396.98/192,371.94 = 78,976.20/x
3. Step 3: Cross multiply
   139,396.98x = 192,371.94 × 78,976.20
4. Step 4: Simplify right side
   139,396.98x = 15,192,804,807.83
5. Step 5: Solve for x
   x = 15,192,804,807.83/139,396.98
6. Step 6: Final answer
   x = 108,989.48