Finding the Third Proportional to 272,644 and 418,500

Step by Step Solution

1. Step 1: Write the proportion equation
   272,644 : 418,500 = 418,500 : x
2. Step 2: Convert to fraction form
   272,644/418,500 = 418,500/x
3. Step 3: Cross multiply
   272,644x = 418,500 × 418,500
4. Step 4: Simplify right side
   272,644x = 175,142,250,000
5. Step 5: Solve for x
   x = 175,142,250,000/272,644
6. Step 6: Final answer
   x = 642,384.39