Finding the Fourth Proportional to 2,275, 3,139.50 and 1,280.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,275 : 3,139.50 = 1,280.28 : x
2. Step 2: Convert to fraction form
   2,275/3,139.50 = 1,280.28/x
3. Step 3: Cross multiply
   2,275x = 3,139.50 × 1,280.28
4. Step 4: Simplify right side
   2,275x = 4,019,439.06
5. Step 5: Solve for x
   x = 4,019,439.06/2,275
6. Step 6: Final answer
   x = 1,766.79