Finding the Third Proportional to 685,901 and 978,406

Step by Step Solution

1. Step 1: Write the proportion equation
   685,901 : 978,406 = 978,406 : x
2. Step 2: Convert to fraction form
   685,901/978,406 = 978,406/x
3. Step 3: Cross multiply
   685,901x = 978,406 × 978,406
4. Step 4: Simplify right side
   685,901x = 957,278,300,836
5. Step 5: Solve for x
   x = 957,278,300,836/685,901
6. Step 6: Final answer
   x = 1,395,650.83