Finding the Fourth Proportional to 1,275.89, 1,761.27 and 778.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,275.89 : 1,761.27 = 778.71 : x
2. Step 2: Convert to fraction form
   1,275.89/1,761.27 = 778.71/x
3. Step 3: Cross multiply
   1,275.89x = 1,761.27 × 778.71
4. Step 4: Simplify right side
   1,275.89x = 1,371,505.86
5. Step 5: Solve for x
   x = 1,371,505.86/1,275.89
6. Step 6: Final answer
   x = 1,074.94