Finding the Fourth Proportional to 2,574.78, 3,861.42 and 1,257.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,574.78 : 3,861.42 = 1,257.72 : x
2. Step 2: Convert to fraction form
   2,574.78/3,861.42 = 1,257.72/x
3. Step 3: Cross multiply
   2,574.78x = 3,861.42 × 1,257.72
4. Step 4: Simplify right side
   2,574.78x = 4,856,585.16
5. Step 5: Solve for x
   x = 4,856,585.16/2,574.78
6. Step 6: Final answer
   x = 1,886.21