Finding the Fourth Proportional to 139,632.78, 207,869.77 and 138,802.40

Step by Step Solution

1. Step 1: Write the proportion equation
   139,632.78 : 207,869.77 = 138,802.40 : x
2. Step 2: Convert to fraction form
   139,632.78/207,869.77 = 138,802.40/x
3. Step 3: Cross multiply
   139,632.78x = 207,869.77 × 138,802.40
4. Step 4: Simplify right side
   139,632.78x = 28,852,822,963.45
5. Step 5: Solve for x
   x = 28,852,822,963.45/139,632.78
6. Step 6: Final answer
   x = 206,633.59