Finding the Third Proportional to 685,892.25 and 978,394.50

Step by Step Solution

1. Step 1: Write the proportion equation
   685,892.25 : 978,394.50 = 978,394.50 : x
2. Step 2: Convert to fraction form
   685,892.25/978,394.50 = 978,394.50/x
3. Step 3: Cross multiply
   685,892.25x = 978,394.50 × 978,394.50
4. Step 4: Simplify right side
   685,892.25x = 957,255,797,630.25
5. Step 5: Solve for x
   x = 957,255,797,630.25/685,892.25
6. Step 6: Final answer
   x = 1,395,635.83