Finding the Third Proportional to 445,686 and 690,410

Step by Step Solution

1. Step 1: Write the proportion equation
   445,686 : 690,410 = 690,410 : x
2. Step 2: Convert to fraction form
   445,686/690,410 = 690,410/x
3. Step 3: Cross multiply
   445,686x = 690,410 × 690,410
4. Step 4: Simplify right side
   445,686x = 476,665,968,100
5. Step 5: Solve for x
   x = 476,665,968,100/445,686
6. Step 6: Final answer
   x = 1,069,510.75