Finding the Third Proportional to 389,616 and 622,405.50

Step by Step Solution

1. Step 1: Write the proportion equation
   389,616 : 622,405.50 = 622,405.50 : x
2. Step 2: Convert to fraction form
   389,616/622,405.50 = 622,405.50/x
3. Step 3: Cross multiply
   389,616x = 622,405.50 × 622,405.50
4. Step 4: Simplify right side
   389,616x = 387,388,606,430.25
5. Step 5: Solve for x
   x = 387,388,606,430.25/389,616
6. Step 6: Final answer
   x = 994,283.11