Finding the Fourth Proportional to 620,047.31, 855,603.61 and 378,389.27

Step by Step Solution

1. Step 1: Write the proportion equation
   620,047.31 : 855,603.61 = 378,389.27 : x
2. Step 2: Convert to fraction form
   620,047.31/855,603.61 = 378,389.27/x
3. Step 3: Cross multiply
   620,047.31x = 855,603.61 × 378,389.27
4. Step 4: Simplify right side
   620,047.31x = 323,751,226,590.30
5. Step 5: Solve for x
   x = 323,751,226,590.30/620,047.31
6. Step 6: Final answer
   x = 522,139.56