Finding the Third Proportional to 298,910 and 646,662

Step by Step Solution

1. Step 1: Write the proportion equation
   298,910 : 646,662 = 646,662 : x
2. Step 2: Convert to fraction form
   298,910/646,662 = 646,662/x
3. Step 3: Cross multiply
   298,910x = 646,662 × 646,662
4. Step 4: Simplify right side
   298,910x = 418,171,742,244
5. Step 5: Solve for x
   x = 418,171,742,244/298,910
6. Step 6: Final answer
   x = 1,398,988.80