Finding the Third Proportional to 290,202 and 443,640

Step by Step Solution

1. Step 1: Write the proportion equation
   290,202 : 443,640 = 443,640 : x
2. Step 2: Convert to fraction form
   290,202/443,640 = 443,640/x
3. Step 3: Cross multiply
   290,202x = 443,640 × 443,640
4. Step 4: Simplify right side
   290,202x = 196,816,449,600
5. Step 5: Solve for x
   x = 196,816,449,600/290,202
6. Step 6: Final answer
   x = 678,205.01