Finding the Third Proportional to 217,405 and 300,406

Step by Step Solution

1. Step 1: Write the proportion equation
   217,405 : 300,406 = 300,406 : x
2. Step 2: Convert to fraction form
   217,405/300,406 = 300,406/x
3. Step 3: Cross multiply
   217,405x = 300,406 × 300,406
4. Step 4: Simplify right side
   217,405x = 90,243,764,836
5. Step 5: Solve for x
   x = 90,243,764,836/217,405
6. Step 6: Final answer
   x = 415,095.17