Finding the Third Proportional to 445,500 and 643,670

Step by Step Solution

1. Step 1: Write the proportion equation
   445,500 : 643,670 = 643,670 : x
2. Step 2: Convert to fraction form
   445,500/643,670 = 643,670/x
3. Step 3: Cross multiply
   445,500x = 643,670 × 643,670
4. Step 4: Simplify right side
   445,500x = 414,311,068,900
5. Step 5: Solve for x
   x = 414,311,068,900/445,500
6. Step 6: Final answer
   x = 929,991.18