Finding the Third Proportional to 408,074 and 621,144

Step by Step Solution

1. Step 1: Write the proportion equation
   408,074 : 621,144 = 621,144 : x
2. Step 2: Convert to fraction form
   408,074/621,144 = 621,144/x
3. Step 3: Cross multiply
   408,074x = 621,144 × 621,144
4. Step 4: Simplify right side
   408,074x = 385,819,868,736
5. Step 5: Solve for x
   x = 385,819,868,736/408,074
6. Step 6: Final answer
   x = 945,465.45