Finding the Third Proportional to 290,204 and 443,643

Step by Step Solution

1. Step 1: Write the proportion equation
   290,204 : 443,643 = 443,643 : x
2. Step 2: Convert to fraction form
   290,204/443,643 = 443,643/x
3. Step 3: Cross multiply
   290,204x = 443,643 × 443,643
4. Step 4: Simplify right side
   290,204x = 196,819,111,449
5. Step 5: Solve for x
   x = 196,819,111,449/290,204
6. Step 6: Final answer
   x = 678,209.51