Finding the Third Proportional to 102,640 and 213,443

Step by Step Solution

1. Step 1: Write the proportion equation
   102,640 : 213,443 = 213,443 : x
2. Step 2: Convert to fraction form
   102,640/213,443 = 213,443/x
3. Step 3: Cross multiply
   102,640x = 213,443 × 213,443
4. Step 4: Simplify right side
   102,640x = 45,557,914,249
5. Step 5: Solve for x
   x = 45,557,914,249/102,640
6. Step 6: Final answer
   x = 443,861.21