Finding the Fourth Proportional to 1,005.71, 1,387.86 and 563.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.71 : 1,387.86 = 563.72 : x
2. Step 2: Convert to fraction form
   1,005.71/1,387.86 = 563.72/x
3. Step 3: Cross multiply
   1,005.71x = 1,387.86 × 563.72
4. Step 4: Simplify right side
   1,005.71x = 782,357.50
5. Step 5: Solve for x
   x = 782,357.50/1,005.71
6. Step 6: Final answer
   x = 777.92