Finding the Fourth Proportional to 2,581.56, 3,872.70 and 849.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,581.56 : 3,872.70 = 849.78 : x
2. Step 2: Convert to fraction form
   2,581.56/3,872.70 = 849.78/x
3. Step 3: Cross multiply
   2,581.56x = 3,872.70 × 849.78
4. Step 4: Simplify right side
   2,581.56x = 3,290,943.01
5. Step 5: Solve for x
   x = 3,290,943.01/2,581.56
6. Step 6: Final answer
   x = 1,274.79