Finding the Third Proportional to 643,839.50 and 1,340,665

Step by Step Solution

1. Step 1: Write the proportion equation
   643,839.50 : 1,340,665 = 1,340,665 : x
2. Step 2: Convert to fraction form
   643,839.50/1,340,665 = 1,340,665/x
3. Step 3: Cross multiply
   643,839.50x = 1,340,665 × 1,340,665
4. Step 4: Simplify right side
   643,839.50x = 1,797,382,642,225
5. Step 5: Solve for x
   x = 1,797,382,642,225/643,839.50
6. Step 6: Final answer
   x = 2,791,662.58