Finding the Third Proportional to 682.31 and 1,057.78

Step by Step Solution

1. Step 1: Write the proportion equation
   682.31 : 1,057.78 = 1,057.78 : x
2. Step 2: Convert to fraction form
   682.31/1,057.78 = 1,057.78/x
3. Step 3: Cross multiply
   682.31x = 1,057.78 × 1,057.78
4. Step 4: Simplify right side
   682.31x = 1,118,901.17
5. Step 5: Solve for x
   x = 1,118,901.17/682.31
6. Step 6: Final answer
   x = 1,639.87