Finding the Third Proportional to 643,443.59 and 1,386,617.80

Step by Step Solution

1. Step 1: Write the proportion equation
   643,443.59 : 1,386,617.80 = 1,386,617.80 : x
2. Step 2: Convert to fraction form
   643,443.59/1,386,617.80 = 1,386,617.80/x
3. Step 3: Cross multiply
   643,443.59x = 1,386,617.80 × 1,386,617.80
4. Step 4: Simplify right side
   643,443.59x = 1,922,708,925,443.29
5. Step 5: Solve for x
   x = 1,922,708,925,443.29/643,443.59
6. Step 6: Final answer
   x = 2,988,154.59