Finding the Fourth Proportional to 2,275.20, 3,139.52 and 1,280.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,275.20 : 3,139.52 = 1,280.56 : x
2. Step 2: Convert to fraction form
   2,275.20/3,139.52 = 1,280.56/x
3. Step 3: Cross multiply
   2,275.20x = 3,139.52 × 1,280.56
4. Step 4: Simplify right side
   2,275.20x = 4,020,343.73
5. Step 5: Solve for x
   x = 4,020,343.73/2,275.20
6. Step 6: Final answer
   x = 1,767.03