Finding the Fourth Proportional to 139,387.71, 209,007.45 and 55,144.47

Step by Step Solution

1. Step 1: Write the proportion equation
   139,387.71 : 209,007.45 = 55,144.47 : x
2. Step 2: Convert to fraction form
   139,387.71/209,007.45 = 55,144.47/x
3. Step 3: Cross multiply
   139,387.71x = 209,007.45 × 55,144.47
4. Step 4: Simplify right side
   139,387.71x = 11,525,605,056.30
5. Step 5: Solve for x
   x = 11,525,605,056.30/139,387.71
6. Step 6: Final answer
   x = 82,687.38