Finding the Third Proportional to 416,826 and 645,039

Step by Step Solution

1. Step 1: Write the proportion equation
   416,826 : 645,039 = 645,039 : x
2. Step 2: Convert to fraction form
   416,826/645,039 = 645,039/x
3. Step 3: Cross multiply
   416,826x = 645,039 × 645,039
4. Step 4: Simplify right side
   416,826x = 416,075,311,521
5. Step 5: Solve for x
   x = 416,075,311,521/416,826
6. Step 6: Final answer
   x = 998,199.04