Finding the Third Proportional to 423,144 and 648,144

Step by Step Solution

1. Step 1: Write the proportion equation
   423,144 : 648,144 = 648,144 : x
2. Step 2: Convert to fraction form
   423,144/648,144 = 648,144/x
3. Step 3: Cross multiply
   423,144x = 648,144 × 648,144
4. Step 4: Simplify right side
   423,144x = 420,090,644,736
5. Step 5: Solve for x
   x = 420,090,644,736/423,144
6. Step 6: Final answer
   x = 992,784.12