Finding the Third Proportional to 64,519 and 139,243

Step by Step Solution

1. Step 1: Write the proportion equation
   64,519 : 139,243 = 139,243 : x
2. Step 2: Convert to fraction form
   64,519/139,243 = 139,243/x
3. Step 3: Cross multiply
   64,519x = 139,243 × 139,243
4. Step 4: Simplify right side
   64,519x = 19,388,613,049
5. Step 5: Solve for x
   x = 19,388,613,049/64,519
6. Step 6: Final answer
   x = 300,510.13