Finding the Fourth Proportional to 1,861.89, 2,790.39 and 1,040.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,861.89 : 2,790.39 = 1,040.55 : x
2. Step 2: Convert to fraction form
   1,861.89/2,790.39 = 1,040.55/x
3. Step 3: Cross multiply
   1,861.89x = 2,790.39 × 1,040.55
4. Step 4: Simplify right side
   1,861.89x = 2,903,540.31
5. Step 5: Solve for x
   x = 2,903,540.31/1,861.89
6. Step 6: Final answer
   x = 1,559.46