Finding the Third Proportional to 640,966 and 978,399

Step by Step Solution

1. Step 1: Write the proportion equation
   640,966 : 978,399 = 978,399 : x
2. Step 2: Convert to fraction form
   640,966/978,399 = 978,399/x
3. Step 3: Cross multiply
   640,966x = 978,399 × 978,399
4. Step 4: Simplify right side
   640,966x = 957,264,603,201
5. Step 5: Solve for x
   x = 957,264,603,201/640,966
6. Step 6: Final answer
   x = 1,493,471.73