Finding the Fourth Proportional to 57,139.20, 78,768.18 and 40,091.94

Step by Step Solution

1. Step 1: Write the proportion equation
   57,139.20 : 78,768.18 = 40,091.94 : x
2. Step 2: Convert to fraction form
   57,139.20/78,768.18 = 40,091.94/x
3. Step 3: Cross multiply
   57,139.20x = 78,768.18 × 40,091.94
4. Step 4: Simplify right side
   57,139.20x = 3,157,969,146.47
5. Step 5: Solve for x
   x = 3,157,969,146.47/57,139.20
6. Step 6: Final answer
   x = 55,268.00