Finding the Fourth Proportional to 279,856.20, 419,479.24 and 137,418.72

Step by Step Solution

1. Step 1: Write the proportion equation
   279,856.20 : 419,479.24 = 137,418.72 : x
2. Step 2: Convert to fraction form
   279,856.20/419,479.24 = 137,418.72/x
3. Step 3: Cross multiply
   279,856.20x = 419,479.24 × 137,418.72
4. Step 4: Simplify right side
   279,856.20x = 57,644,300,227.37
5. Step 5: Solve for x
   x = 57,644,300,227.37/279,856.20
6. Step 6: Final answer
   x = 205,978.29