Finding the Fourth Proportional to 1,387.43, 1,914.77 and 863.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.43 : 1,914.77 = 863.54 : x
2. Step 2: Convert to fraction form
   1,387.43/1,914.77 = 863.54/x
3. Step 3: Cross multiply
   1,387.43x = 1,914.77 × 863.54
4. Step 4: Simplify right side
   1,387.43x = 1,653,476.17
5. Step 5: Solve for x
   x = 1,653,476.17/1,387.43
6. Step 6: Final answer
   x = 1,191.75