Finding the Third Proportional to 401,588 and 645,800

Step by Step Solution

1. Step 1: Write the proportion equation
   401,588 : 645,800 = 645,800 : x
2. Step 2: Convert to fraction form
   401,588/645,800 = 645,800/x
3. Step 3: Cross multiply
   401,588x = 645,800 × 645,800
4. Step 4: Simplify right side
   401,588x = 417,057,640,000
5. Step 5: Solve for x
   x = 417,057,640,000/401,588
6. Step 6: Final answer
   x = 1,038,521.17