Finding the Third Proportional to 210,772 and 321,510

Step by Step Solution

1. Step 1: Write the proportion equation
   210,772 : 321,510 = 321,510 : x
2. Step 2: Convert to fraction form
   210,772/321,510 = 321,510/x
3. Step 3: Cross multiply
   210,772x = 321,510 × 321,510
4. Step 4: Simplify right side
   210,772x = 103,368,680,100
5. Step 5: Solve for x
   x = 103,368,680,100/210,772
6. Step 6: Final answer
   x = 490,428.90