Finding the Third Proportional to 389,812 and 839,780

Step by Step Solution

1. Step 1: Write the proportion equation
   389,812 : 839,780 = 839,780 : x
2. Step 2: Convert to fraction form
   389,812/839,780 = 839,780/x
3. Step 3: Cross multiply
   389,812x = 839,780 × 839,780
4. Step 4: Simplify right side
   389,812x = 705,230,448,400
5. Step 5: Solve for x
   x = 705,230,448,400/389,812
6. Step 6: Final answer
   x = 1,809,155.31