Finding the Fourth Proportional to 2,459.20, 3,687.84 and 815.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,459.20 : 3,687.84 = 815.31 : x
2. Step 2: Convert to fraction form
   2,459.20/3,687.84 = 815.31/x
3. Step 3: Cross multiply
   2,459.20x = 3,687.84 × 815.31
4. Step 4: Simplify right side
   2,459.20x = 3,006,732.83
5. Step 5: Solve for x
   x = 3,006,732.83/2,459.20
6. Step 6: Final answer
   x = 1,222.65