Finding the Third Proportional to 64,990 and 139,651

Step by Step Solution

1. Step 1: Write the proportion equation
   64,990 : 139,651 = 139,651 : x
2. Step 2: Convert to fraction form
   64,990/139,651 = 139,651/x
3. Step 3: Cross multiply
   64,990x = 139,651 × 139,651
4. Step 4: Simplify right side
   64,990x = 19,502,401,801
5. Step 5: Solve for x
   x = 19,502,401,801/64,990
6. Step 6: Final answer
   x = 300,083.12