Finding the Third Proportional to 139,272 and 212,172

Step by Step Solution

1. Step 1: Write the proportion equation
   139,272 : 212,172 = 212,172 : x
2. Step 2: Convert to fraction form
   139,272/212,172 = 212,172/x
3. Step 3: Cross multiply
   139,272x = 212,172 × 212,172
4. Step 4: Simplify right side
   139,272x = 45,016,957,584
5. Step 5: Solve for x
   x = 45,016,957,584/139,272
6. Step 6: Final answer
   x = 323,230.50