Finding the Fourth Proportional to 1,387.59, 1,914.60 and 863.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.59 : 1,914.60 = 863.38 : x
2. Step 2: Convert to fraction form
   1,387.59/1,914.60 = 863.38/x
3. Step 3: Cross multiply
   1,387.59x = 1,914.60 × 863.38
4. Step 4: Simplify right side
   1,387.59x = 1,653,027.35
5. Step 5: Solve for x
   x = 1,653,027.35/1,387.59
6. Step 6: Final answer
   x = 1,191.29