Finding the Third Proportional to 139,272 and 209,217

Step by Step Solution

1. Step 1: Write the proportion equation
   139,272 : 209,217 = 209,217 : x
2. Step 2: Convert to fraction form
   139,272/209,217 = 209,217/x
3. Step 3: Cross multiply
   139,272x = 209,217 × 209,217
4. Step 4: Simplify right side
   139,272x = 43,771,753,089
5. Step 5: Solve for x
   x = 43,771,753,089/139,272
6. Step 6: Final answer
   x = 314,289.69