Finding the Third Proportional to 321,568 and 689,792

Step by Step Solution

1. Step 1: Write the proportion equation
   321,568 : 689,792 = 689,792 : x
2. Step 2: Convert to fraction form
   321,568/689,792 = 689,792/x
3. Step 3: Cross multiply
   321,568x = 689,792 × 689,792
4. Step 4: Simplify right side
   321,568x = 475,813,003,264
5. Step 5: Solve for x
   x = 475,813,003,264/321,568
6. Step 6: Final answer
   x = 1,479,665.28