Finding the Fourth Proportional to 389,978.53, 538,120.90 and 228,774.76

Step by Step Solution

1. Step 1: Write the proportion equation
   389,978.53 : 538,120.90 = 228,774.76 : x
2. Step 2: Convert to fraction form
   389,978.53/538,120.90 = 228,774.76/x
3. Step 3: Cross multiply
   389,978.53x = 538,120.90 × 228,774.76
4. Step 4: Simplify right side
   389,978.53x = 123,108,481,716.08
5. Step 5: Solve for x
   x = 123,108,481,716.08/389,978.53
6. Step 6: Final answer
   x = 315,680.15