Finding the Third Proportional to 646,678 and 978,960

Step by Step Solution

1. Step 1: Write the proportion equation
   646,678 : 978,960 = 978,960 : x
2. Step 2: Convert to fraction form
   646,678/978,960 = 978,960/x
3. Step 3: Cross multiply
   646,678x = 978,960 × 978,960
4. Step 4: Simplify right side
   646,678x = 958,362,681,600
5. Step 5: Solve for x
   x = 958,362,681,600/646,678
6. Step 6: Final answer
   x = 1,481,978.17