Finding the Third Proportional to 405,829.50 and 642,585

Step by Step Solution

1. Step 1: Write the proportion equation
   405,829.50 : 642,585 = 642,585 : x
2. Step 2: Convert to fraction form
   405,829.50/642,585 = 642,585/x
3. Step 3: Cross multiply
   405,829.50x = 642,585 × 642,585
4. Step 4: Simplify right side
   405,829.50x = 412,915,482,225
5. Step 5: Solve for x
   x = 412,915,482,225/405,829.50
6. Step 6: Final answer
   x = 1,017,460.49