Finding the Third Proportional to 212,290 and 309,684

Step by Step Solution

1. Step 1: Write the proportion equation
   212,290 : 309,684 = 309,684 : x
2. Step 2: Convert to fraction form
   212,290/309,684 = 309,684/x
3. Step 3: Cross multiply
   212,290x = 309,684 × 309,684
4. Step 4: Simplify right side
   212,290x = 95,904,179,856
5. Step 5: Solve for x
   x = 95,904,179,856/212,290
6. Step 6: Final answer
   x = 451,760.23