Finding the Fourth Proportional to 1,005.15, 1,387.10 and 563.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.15 : 1,387.10 = 563.06 : x
2. Step 2: Convert to fraction form
   1,005.15/1,387.10 = 563.06/x
3. Step 3: Cross multiply
   1,005.15x = 1,387.10 × 563.06
4. Step 4: Simplify right side
   1,005.15x = 781,010.78
5. Step 5: Solve for x
   x = 781,010.78/1,005.15
6. Step 6: Final answer
   x = 777.01