Finding the Fourth Proportional to 2,123.06, 3,183.12 and 806.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.06 : 3,183.12 = 806.90 : x
2. Step 2: Convert to fraction form
   2,123.06/3,183.12 = 806.90/x
3. Step 3: Cross multiply
   2,123.06x = 3,183.12 × 806.90
4. Step 4: Simplify right side
   2,123.06x = 2,568,459.31
5. Step 5: Solve for x
   x = 2,568,459.31/2,123.06
6. Step 6: Final answer
   x = 1,209.79