Finding the Third Proportional to 288,816 and 644,039.25

Step by Step Solution

1. Step 1: Write the proportion equation
   288,816 : 644,039.25 = 644,039.25 : x
2. Step 2: Convert to fraction form
   288,816/644,039.25 = 644,039.25/x
3. Step 3: Cross multiply
   288,816x = 644,039.25 × 644,039.25
4. Step 4: Simplify right side
   288,816x = 414,786,555,540.56
5. Step 5: Solve for x
   x = 414,786,555,540.56/288,816
6. Step 6: Final answer
   x = 1,436,161.97