Finding the Fourth Proportional to 309,142.67, 428,799.51 and 300,948.71

Step by Step Solution

1. Step 1: Write the proportion equation
   309,142.67 : 428,799.51 = 300,948.71 : x
2. Step 2: Convert to fraction form
   309,142.67/428,799.51 = 300,948.71/x
3. Step 3: Cross multiply
   309,142.67x = 428,799.51 × 300,948.71
4. Step 4: Simplify right side
   309,142.67x = 129,046,657,878.39
5. Step 5: Solve for x
   x = 129,046,657,878.39/309,142.67
6. Step 6: Final answer
   x = 417,433.99