Finding the Third Proportional to 212,931 and 329,648

Step by Step Solution

1. Step 1: Write the proportion equation
   212,931 : 329,648 = 329,648 : x
2. Step 2: Convert to fraction form
   212,931/329,648 = 329,648/x
3. Step 3: Cross multiply
   212,931x = 329,648 × 329,648
4. Step 4: Simplify right side
   212,931x = 108,667,803,904
5. Step 5: Solve for x
   x = 108,667,803,904/212,931
6. Step 6: Final answer
   x = 510,342.81