Finding the Fourth Proportional to 3,131.10, 4,320.90 and 1,805.05

Step by Step Solution

1. Step 1: Write the proportion equation
   3,131.10 : 4,320.90 = 1,805.05 : x
2. Step 2: Convert to fraction form
   3,131.10/4,320.90 = 1,805.05/x
3. Step 3: Cross multiply
   3,131.10x = 4,320.90 × 1,805.05
4. Step 4: Simplify right side
   3,131.10x = 7,799,440.55
5. Step 5: Solve for x
   x = 7,799,440.55/3,131.10
6. Step 6: Final answer
   x = 2,490.96