Finding the Fourth Proportional to 2,856.59, 3,940.94 and 1,861.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,856.59 : 3,940.94 = 1,861.50 : x
2. Step 2: Convert to fraction form
   2,856.59/3,940.94 = 1,861.50/x
3. Step 3: Cross multiply
   2,856.59x = 3,940.94 × 1,861.50
4. Step 4: Simplify right side
   2,856.59x = 7,336,050.50
5. Step 5: Solve for x
   x = 7,336,050.50/2,856.59
6. Step 6: Final answer
   x = 2,568.12