Finding the Fourth Proportional to 1,005.31, 1,387.33 and 563.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.31 : 1,387.33 = 563.32 : x
2. Step 2: Convert to fraction form
   1,005.31/1,387.33 = 563.32/x
3. Step 3: Cross multiply
   1,005.31x = 1,387.33 × 563.32
4. Step 4: Simplify right side
   1,005.31x = 781,510.74
5. Step 5: Solve for x
   x = 781,510.74/1,005.31
6. Step 6: Final answer
   x = 777.38