Finding the Fourth Proportional to 1,005.46, 1,387.61 and 563.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.46 : 1,387.61 = 563.40 : x
2. Step 2: Convert to fraction form
   1,005.46/1,387.61 = 563.40/x
3. Step 3: Cross multiply
   1,005.46x = 1,387.61 × 563.40
4. Step 4: Simplify right side
   1,005.46x = 781,781.94
5. Step 5: Solve for x
   x = 781,781.94/1,005.46
6. Step 6: Final answer
   x = 777.54