Finding the Third Proportional to 388,406 and 830,780

Step by Step Solution

1. Step 1: Write the proportion equation
   388,406 : 830,780 = 830,780 : x
2. Step 2: Convert to fraction form
   388,406/830,780 = 830,780/x
3. Step 3: Cross multiply
   388,406x = 830,780 × 830,780
4. Step 4: Simplify right side
   388,406x = 690,195,408,400
5. Step 5: Solve for x
   x = 690,195,408,400/388,406
6. Step 6: Final answer
   x = 1,776,994.71