Finding the Third Proportional to 640,936 and 978,353

Step by Step Solution

1. Step 1: Write the proportion equation
   640,936 : 978,353 = 978,353 : x
2. Step 2: Convert to fraction form
   640,936/978,353 = 978,353/x
3. Step 3: Cross multiply
   640,936x = 978,353 × 978,353
4. Step 4: Simplify right side
   640,936x = 957,174,592,609
5. Step 5: Solve for x
   x = 957,174,592,609/640,936
6. Step 6: Final answer
   x = 1,493,401.20