Finding the Third Proportional to 210,474 and 321,978

Step by Step Solution

1. Step 1: Write the proportion equation
   210,474 : 321,978 = 321,978 : x
2. Step 2: Convert to fraction form
   210,474/321,978 = 321,978/x
3. Step 3: Cross multiply
   210,474x = 321,978 × 321,978
4. Step 4: Simplify right side
   210,474x = 103,669,832,484
5. Step 5: Solve for x
   x = 103,669,832,484/210,474
6. Step 6: Final answer
   x = 492,554.10