Finding the Fourth Proportional to 685,499.47, 946,096.05 and 391,149.78

Step by Step Solution

1. Step 1: Write the proportion equation
   685,499.47 : 946,096.05 = 391,149.78 : x
2. Step 2: Convert to fraction form
   685,499.47/946,096.05 = 391,149.78/x
3. Step 3: Cross multiply
   685,499.47x = 946,096.05 × 391,149.78
4. Step 4: Simplify right side
   685,499.47x = 370,065,261,816.37
5. Step 5: Solve for x
   x = 370,065,261,816.37/685,499.47
6. Step 6: Final answer
   x = 539,847.63