Finding the Fourth Proportional to 1,005.71, 1,512.89 and 863.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.71 : 1,512.89 = 863.15 : x
2. Step 2: Convert to fraction form
   1,005.71/1,512.89 = 863.15/x
3. Step 3: Cross multiply
   1,005.71x = 1,512.89 × 863.15
4. Step 4: Simplify right side
   1,005.71x = 1,305,846.69
5. Step 5: Solve for x
   x = 1,305,846.69/1,005.71
6. Step 6: Final answer
   x = 1,298.43