Finding the Third Proportional to 210,772 and 321,410

Step by Step Solution

1. Step 1: Write the proportion equation
   210,772 : 321,410 = 321,410 : x
2. Step 2: Convert to fraction form
   210,772/321,410 = 321,410/x
3. Step 3: Cross multiply
   210,772x = 321,410 × 321,410
4. Step 4: Simplify right side
   210,772x = 103,304,388,100
5. Step 5: Solve for x
   x = 103,304,388,100/210,772
6. Step 6: Final answer
   x = 490,123.87