Finding the Third Proportional to 309,219 and 665,185.50

Step by Step Solution

1. Step 1: Write the proportion equation
   309,219 : 665,185.50 = 665,185.50 : x
2. Step 2: Convert to fraction form
   309,219/665,185.50 = 665,185.50/x
3. Step 3: Cross multiply
   309,219x = 665,185.50 × 665,185.50
4. Step 4: Simplify right side
   309,219x = 442,471,749,410.25
5. Step 5: Solve for x
   x = 442,471,749,410.25/309,219
6. Step 6: Final answer
   x = 1,430,933.25