Finding the Fourth Proportional to 2,081.90, 3,120.12 and 1,861.22

Step by Step Solution

1. Step 1: Write the proportion equation
   2,081.90 : 3,120.12 = 1,861.22 : x
2. Step 2: Convert to fraction form
   2,081.90/3,120.12 = 1,861.22/x
3. Step 3: Cross multiply
   2,081.90x = 3,120.12 × 1,861.22
4. Step 4: Simplify right side
   2,081.90x = 5,807,214.15
5. Step 5: Solve for x
   x = 5,807,214.15/2,081.90
6. Step 6: Final answer
   x = 2,789.39