Finding the Third Proportional to 643,802 and 1,385,780

Step by Step Solution

1. Step 1: Write the proportion equation
   643,802 : 1,385,780 = 1,385,780 : x
2. Step 2: Convert to fraction form
   643,802/1,385,780 = 1,385,780/x
3. Step 3: Cross multiply
   643,802x = 1,385,780 × 1,385,780
4. Step 4: Simplify right side
   643,802x = 1,920,386,208,400
5. Step 5: Solve for x
   x = 1,920,386,208,400/643,802
6. Step 6: Final answer
   x = 2,982,883.26