Finding the Fourth Proportional to 1,356.39, 1,871.72 and 766.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.39 : 1,871.72 = 766.91 : x
2. Step 2: Convert to fraction form
   1,356.39/1,871.72 = 766.91/x
3. Step 3: Cross multiply
   1,356.39x = 1,871.72 × 766.91
4. Step 4: Simplify right side
   1,356.39x = 1,435,440.79
5. Step 5: Solve for x
   x = 1,435,440.79/1,356.39
6. Step 6: Final answer
   x = 1,058.28