Finding the Third Proportional to 307,686 and 664,579.50

Step by Step Solution

1. Step 1: Write the proportion equation
   307,686 : 664,579.50 = 664,579.50 : x
2. Step 2: Convert to fraction form
   307,686/664,579.50 = 664,579.50/x
3. Step 3: Cross multiply
   307,686x = 664,579.50 × 664,579.50
4. Step 4: Simplify right side
   307,686x = 441,665,911,820.25
5. Step 5: Solve for x
   x = 441,665,911,820.25/307,686
6. Step 6: Final answer
   x = 1,435,443.64