Finding the Third Proportional to 394,416 and 640,804.50

Step by Step Solution

1. Step 1: Write the proportion equation
   394,416 : 640,804.50 = 640,804.50 : x
2. Step 2: Convert to fraction form
   394,416/640,804.50 = 640,804.50/x
3. Step 3: Cross multiply
   394,416x = 640,804.50 × 640,804.50
4. Step 4: Simplify right side
   394,416x = 410,630,407,220.25
5. Step 5: Solve for x
   x = 410,630,407,220.25/394,416
6. Step 6: Final answer
   x = 1,041,109.91