Finding the Fourth Proportional to 1,355.91, 1,871.10 and 766.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.91 : 1,871.10 = 766.41 : x
2. Step 2: Convert to fraction form
   1,355.91/1,871.10 = 766.41/x
3. Step 3: Cross multiply
   1,355.91x = 1,871.10 × 766.41
4. Step 4: Simplify right side
   1,355.91x = 1,434,029.75
5. Step 5: Solve for x
   x = 1,434,029.75/1,355.91
6. Step 6: Final answer
   x = 1,057.61