Finding the Third Proportional to 414,879.75 and 640,746

Step by Step Solution

1. Step 1: Write the proportion equation
   414,879.75 : 640,746 = 640,746 : x
2. Step 2: Convert to fraction form
   414,879.75/640,746 = 640,746/x
3. Step 3: Cross multiply
   414,879.75x = 640,746 × 640,746
4. Step 4: Simplify right side
   414,879.75x = 410,555,436,516
5. Step 5: Solve for x
   x = 410,555,436,516/414,879.75
6. Step 6: Final answer
   x = 989,576.95