Finding the Fourth Proportional to 56,640.78, 78,204.83 and 39,682.62

Step by Step Solution

1. Step 1: Write the proportion equation
   56,640.78 : 78,204.83 = 39,682.62 : x
2. Step 2: Convert to fraction form
   56,640.78/78,204.83 = 39,682.62/x
3. Step 3: Cross multiply
   56,640.78x = 78,204.83 × 39,682.62
4. Step 4: Simplify right side
   56,640.78x = 3,103,372,352.64
5. Step 5: Solve for x
   x = 3,103,372,352.64/56,640.78
6. Step 6: Final answer
   x = 54,790.42