Finding the Fourth Proportional to 394,300.46, 591,620.16 and 128,142.56

Step by Step Solution

1. Step 1: Write the proportion equation
   394,300.46 : 591,620.16 = 128,142.56 : x
2. Step 2: Convert to fraction form
   394,300.46/591,620.16 = 128,142.56/x
3. Step 3: Cross multiply
   394,300.46x = 591,620.16 × 128,142.56
4. Step 4: Simplify right side
   394,300.46x = 75,811,721,850.01
5. Step 5: Solve for x
   x = 75,811,721,850.01/394,300.46
6. Step 6: Final answer
   x = 192,268.92