Finding the Fourth Proportional to 1,005.56, 1,387.52 and 563.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.56 : 1,387.52 = 563.40 : x
2. Step 2: Convert to fraction form
   1,005.56/1,387.52 = 563.40/x
3. Step 3: Cross multiply
   1,005.56x = 1,387.52 × 563.40
4. Step 4: Simplify right side
   1,005.56x = 781,728.77
5. Step 5: Solve for x
   x = 781,728.77/1,005.56
6. Step 6: Final answer
   x = 777.41