Finding the Fourth Proportional to 2,857.63, 3,940.90 and 1,862.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,857.63 : 3,940.90 = 1,862.55 : x
2. Step 2: Convert to fraction form
   2,857.63/3,940.90 = 1,862.55/x
3. Step 3: Cross multiply
   2,857.63x = 3,940.90 × 1,862.55
4. Step 4: Simplify right side
   2,857.63x = 7,340,123.30
5. Step 5: Solve for x
   x = 7,340,123.30/2,857.63
6. Step 6: Final answer
   x = 2,568.61