Finding the Fourth Proportional to 2,576.04, 3,862.90 and 820.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,576.04 : 3,862.90 = 820.72 : x
2. Step 2: Convert to fraction form
   2,576.04/3,862.90 = 820.72/x
3. Step 3: Cross multiply
   2,576.04x = 3,862.90 × 820.72
4. Step 4: Simplify right side
   2,576.04x = 3,170,359.29
5. Step 5: Solve for x
   x = 3,170,359.29/2,576.04
6. Step 6: Final answer
   x = 1,230.71