Finding the Fourth Proportional to 139,802.78, 209,517.05 and 50,972.51

Step by Step Solution

1. Step 1: Write the proportion equation
   139,802.78 : 209,517.05 = 50,972.51 : x
2. Step 2: Convert to fraction form
   139,802.78/209,517.05 = 50,972.51/x
3. Step 3: Cross multiply
   139,802.78x = 209,517.05 × 50,972.51
4. Step 4: Simplify right side
   139,802.78x = 10,679,608,623.85
5. Step 5: Solve for x
   x = 10,679,608,623.85/139,802.78
6. Step 6: Final answer
   x = 76,390.53