Finding the Fourth Proportional to 2,275.23, 3,139.63 and 1,280.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,275.23 : 3,139.63 = 1,280.31 : x
2. Step 2: Convert to fraction form
   2,275.23/3,139.63 = 1,280.31/x
3. Step 3: Cross multiply
   2,275.23x = 3,139.63 × 1,280.31
4. Step 4: Simplify right side
   2,275.23x = 4,019,699.69
5. Step 5: Solve for x
   x = 4,019,699.69/2,275.23
6. Step 6: Final answer
   x = 1,766.72