Finding the Fourth Proportional to 685,839.56, 946,920.98 and 428,109.03

Step by Step Solution

1. Step 1: Write the proportion equation
   685,839.56 : 946,920.98 = 428,109.03 : x
2. Step 2: Convert to fraction form
   685,839.56/946,920.98 = 428,109.03/x
3. Step 3: Cross multiply
   685,839.56x = 946,920.98 × 428,109.03
4. Step 4: Simplify right side
   685,839.56x = 405,385,423,304.72
5. Step 5: Solve for x
   x = 405,385,423,304.72/685,839.56
6. Step 6: Final answer
   x = 591,079.09