Finding the Fourth Proportional to 139,631.78, 207,868.28 and 138,801.40

Step by Step Solution

1. Step 1: Write the proportion equation
   139,631.78 : 207,868.28 = 138,801.40 : x
2. Step 2: Convert to fraction form
   139,631.78/207,868.28 = 138,801.40/x
3. Step 3: Cross multiply
   139,631.78x = 207,868.28 × 138,801.40
4. Step 4: Simplify right side
   139,631.78x = 28,852,408,279.59
5. Step 5: Solve for x
   x = 28,852,408,279.59/139,631.78
6. Step 6: Final answer
   x = 206,632.10