Finding the Fourth Proportional to 309,143.67, 428,800.89 and 300,949.71

Step by Step Solution

1. Step 1: Write the proportion equation
   309,143.67 : 428,800.89 = 300,949.71 : x
2. Step 2: Convert to fraction form
   309,143.67/428,800.89 = 300,949.71/x
3. Step 3: Cross multiply
   309,143.67x = 428,800.89 × 300,949.71
4. Step 4: Simplify right side
   309,143.67x = 129,047,503,493.24
5. Step 5: Solve for x
   x = 129,047,503,493.24/309,143.67
6. Step 6: Final answer
   x = 417,435.37