Finding the Fourth Proportional to 2,275.34, 3,139.94 and 1,280.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,275.34 : 3,139.94 = 1,280.61 : x
2. Step 2: Convert to fraction form
   2,275.34/3,139.94 = 1,280.61/x
3. Step 3: Cross multiply
   2,275.34x = 3,139.94 × 1,280.61
4. Step 4: Simplify right side
   2,275.34x = 4,021,041.76
5. Step 5: Solve for x
   x = 4,021,041.76/2,275.34
6. Step 6: Final answer
   x = 1,767.23