Finding the Third Proportional to 643,980 and 1,398,606

Step by Step Solution

1. Step 1: Write the proportion equation
   643,980 : 1,398,606 = 1,398,606 : x
2. Step 2: Convert to fraction form
   643,980/1,398,606 = 1,398,606/x
3. Step 3: Cross multiply
   643,980x = 1,398,606 × 1,398,606
4. Step 4: Simplify right side
   643,980x = 1,956,098,743,236
5. Step 5: Solve for x
   x = 1,956,098,743,236/643,980
6. Step 6: Final answer
   x = 3,037,514.74