Finding the Fourth Proportional to 2,581.67, 3,872.72 and 826.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,581.67 : 3,872.72 = 826.91 : x
2. Step 2: Convert to fraction form
   2,581.67/3,872.72 = 826.91/x
3. Step 3: Cross multiply
   2,581.67x = 3,872.72 × 826.91
4. Step 4: Simplify right side
   2,581.67x = 3,202,390.90
5. Step 5: Solve for x
   x = 3,202,390.90/2,581.67
6. Step 6: Final answer
   x = 1,240.43