Finding the Third Proportional to 640,974 and 978,411

Step by Step Solution

1. Step 1: Write the proportion equation
   640,974 : 978,411 = 978,411 : x
2. Step 2: Convert to fraction form
   640,974/978,411 = 978,411/x
3. Step 3: Cross multiply
   640,974x = 978,411 × 978,411
4. Step 4: Simplify right side
   640,974x = 957,288,084,921
5. Step 5: Solve for x
   x = 957,288,084,921/640,974
6. Step 6: Final answer
   x = 1,493,489.73