Finding the Fourth Proportional to 1,005.57, 1,387.69 and 563.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.57 : 1,387.69 = 563.48 : x
2. Step 2: Convert to fraction form
   1,005.57/1,387.69 = 563.48/x
3. Step 3: Cross multiply
   1,005.57x = 1,387.69 × 563.48
4. Step 4: Simplify right side
   1,005.57x = 781,935.56
5. Step 5: Solve for x
   x = 781,935.56/1,005.57
6. Step 6: Final answer
   x = 777.60