Finding the Fourth Proportional to 1,355.92, 1,871.16 and 766.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.92 : 1,871.16 = 766.57 : x
2. Step 2: Convert to fraction form
   1,355.92/1,871.16 = 766.57/x
3. Step 3: Cross multiply
   1,355.92x = 1,871.16 × 766.57
4. Step 4: Simplify right side
   1,355.92x = 1,434,375.12
5. Step 5: Solve for x
   x = 1,434,375.12/1,355.92
6. Step 6: Final answer
   x = 1,057.86