Finding the Fourth Proportional to 389,866.25, 538,015.56 and 220,111.31

Step by Step Solution

1. Step 1: Write the proportion equation
   389,866.25 : 538,015.56 = 220,111.31 : x
2. Step 2: Convert to fraction form
   389,866.25/538,015.56 = 220,111.31/x
3. Step 3: Cross multiply
   389,866.25x = 538,015.56 × 220,111.31
4. Step 4: Simplify right side
   389,866.25x = 118,423,309,711.98
5. Step 5: Solve for x
   x = 118,423,309,711.98/389,866.25
6. Step 6: Final answer
   x = 303,753.68