Finding the Third Proportional to 685,913 and 978,424

Step by Step Solution

1. Step 1: Write the proportion equation
   685,913 : 978,424 = 978,424 : x
2. Step 2: Convert to fraction form
   685,913/978,424 = 978,424/x
3. Step 3: Cross multiply
   685,913x = 978,424 × 978,424
4. Step 4: Simplify right side
   685,913x = 957,313,523,776
5. Step 5: Solve for x
   x = 957,313,523,776/685,913
6. Step 6: Final answer
   x = 1,395,677.77