Finding the Fourth Proportional to 1,387.82, 1,915.18 and 766.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.82 : 1,915.18 = 766.82 : x
2. Step 2: Convert to fraction form
   1,387.82/1,915.18 = 766.82/x
3. Step 3: Cross multiply
   1,387.82x = 1,915.18 × 766.82
4. Step 4: Simplify right side
   1,387.82x = 1,468,588.75
5. Step 5: Solve for x
   x = 1,468,588.75/1,387.82
6. Step 6: Final answer
   x = 1,058.20