Finding the Fourth Proportional to 1,276.47, 1,761.15 and 772.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,276.47 : 1,761.15 = 772.56 : x
2. Step 2: Convert to fraction form
   1,276.47/1,761.15 = 772.56/x
3. Step 3: Cross multiply
   1,276.47x = 1,761.15 × 772.56
4. Step 4: Simplify right side
   1,276.47x = 1,360,594.04
5. Step 5: Solve for x
   x = 1,360,594.04/1,276.47
6. Step 6: Final answer
   x = 1,065.90