Finding the Fourth Proportional to 2,275.10, 3,139.71 and 1,280.33

Step by Step Solution

1. Step 1: Write the proportion equation
   2,275.10 : 3,139.71 = 1,280.33 : x
2. Step 2: Convert to fraction form
   2,275.10/3,139.71 = 1,280.33/x
3. Step 3: Cross multiply
   2,275.10x = 3,139.71 × 1,280.33
4. Step 4: Simplify right side
   2,275.10x = 4,019,864.90
5. Step 5: Solve for x
   x = 4,019,864.90/2,275.10
6. Step 6: Final answer
   x = 1,766.90