Finding the Third Proportional to 309,216.50 and 665,180

Step by Step Solution

1. Step 1: Write the proportion equation
   309,216.50 : 665,180 = 665,180 : x
2. Step 2: Convert to fraction form
   309,216.50/665,180 = 665,180/x
3. Step 3: Cross multiply
   309,216.50x = 665,180 × 665,180
4. Step 4: Simplify right side
   309,216.50x = 442,464,432,400
5. Step 5: Solve for x
   x = 442,464,432,400/309,216.50
6. Step 6: Final answer
   x = 1,430,921.16