Finding the Third Proportional to 148,658 and 320,644

Step by Step Solution

1. Step 1: Write the proportion equation
   148,658 : 320,644 = 320,644 : x
2. Step 2: Convert to fraction form
   148,658/320,644 = 320,644/x
3. Step 3: Cross multiply
   148,658x = 320,644 × 320,644
4. Step 4: Simplify right side
   148,658x = 102,812,574,736
5. Step 5: Solve for x
   x = 102,812,574,736/148,658
6. Step 6: Final answer
   x = 691,604.72