Finding the Third Proportional to 401,598 and 645,691.50

Step by Step Solution

1. Step 1: Write the proportion equation
   401,598 : 645,691.50 = 645,691.50 : x
2. Step 2: Convert to fraction form
   401,598/645,691.50 = 645,691.50/x
3. Step 3: Cross multiply
   401,598x = 645,691.50 × 645,691.50
4. Step 4: Simplify right side
   401,598x = 416,917,513,172.25
5. Step 5: Solve for x
   x = 416,917,513,172.25/401,598
6. Step 6: Final answer
   x = 1,038,146.39