Finding the Third Proportional to 646,685 and 978,980

Step by Step Solution

1. Step 1: Write the proportion equation
   646,685 : 978,980 = 978,980 : x
2. Step 2: Convert to fraction form
   646,685/978,980 = 978,980/x
3. Step 3: Cross multiply
   646,685x = 978,980 × 978,980
4. Step 4: Simplify right side
   646,685x = 958,401,840,400
5. Step 5: Solve for x
   x = 958,401,840,400/646,685
6. Step 6: Final answer
   x = 1,482,022.69