Finding the Third Proportional to 290,206 and 443,646

Step by Step Solution

1. Step 1: Write the proportion equation
   290,206 : 443,646 = 443,646 : x
2. Step 2: Convert to fraction form
   290,206/443,646 = 443,646/x
3. Step 3: Cross multiply
   290,206x = 443,646 × 443,646
4. Step 4: Simplify right side
   290,206x = 196,821,773,316
5. Step 5: Solve for x
   x = 196,821,773,316/290,206
6. Step 6: Final answer
   x = 678,214.00