Finding the Fourth Proportional to 139,978.92, 209,844.05 and 54,570.09

Step by Step Solution

1. Step 1: Write the proportion equation
   139,978.92 : 209,844.05 = 54,570.09 : x
2. Step 2: Convert to fraction form
   139,978.92/209,844.05 = 54,570.09/x
3. Step 3: Cross multiply
   139,978.92x = 209,844.05 × 54,570.09
4. Step 4: Simplify right side
   139,978.92x = 11,451,208,421.61
5. Step 5: Solve for x
   x = 11,451,208,421.61/139,978.92
6. Step 6: Final answer
   x = 81,806.66