Finding the Third Proportional to 643,440 and 1,413,780

Step by Step Solution

1. Step 1: Write the proportion equation
   643,440 : 1,413,780 = 1,413,780 : x
2. Step 2: Convert to fraction form
   643,440/1,413,780 = 1,413,780/x
3. Step 3: Cross multiply
   643,440x = 1,413,780 × 1,413,780
4. Step 4: Simplify right side
   643,440x = 1,998,773,888,400
5. Step 5: Solve for x
   x = 1,998,773,888,400/643,440
6. Step 6: Final answer
   x = 3,106,387.37