Finding the Third Proportional to 309,078 and 641,833

Step by Step Solution

1. Step 1: Write the proportion equation
   309,078 : 641,833 = 641,833 : x
2. Step 2: Convert to fraction form
   309,078/641,833 = 641,833/x
3. Step 3: Cross multiply
   309,078x = 641,833 × 641,833
4. Step 4: Simplify right side
   309,078x = 411,949,599,889
5. Step 5: Solve for x
   x = 411,949,599,889/309,078
6. Step 6: Final answer
   x = 1,332,833.78