Finding the Third Proportional to 321,870 and 498,660

Step by Step Solution

1. Step 1: Write the proportion equation
   321,870 : 498,660 = 498,660 : x
2. Step 2: Convert to fraction form
   321,870/498,660 = 498,660/x
3. Step 3: Cross multiply
   321,870x = 498,660 × 498,660
4. Step 4: Simplify right side
   321,870x = 248,661,795,600
5. Step 5: Solve for x
   x = 248,661,795,600/321,870
6. Step 6: Final answer
   x = 772,553.50