Finding the Fourth Proportional to 56,899.68, 78,480.85 and 39,907.71

Step by Step Solution

1. Step 1: Write the proportion equation
   56,899.68 : 78,480.85 = 39,907.71 : x
2. Step 2: Convert to fraction form
   56,899.68/78,480.85 = 39,907.71/x
3. Step 3: Cross multiply
   56,899.68x = 78,480.85 × 39,907.71
4. Step 4: Simplify right side
   56,899.68x = 3,131,991,002.35
5. Step 5: Solve for x
   x = 3,131,991,002.35/56,899.68
6. Step 6: Final answer
   x = 55,044.09