Finding the Third Proportional to 64,857 and 139,719

Step by Step Solution

1. Step 1: Write the proportion equation
   64,857 : 139,719 = 139,719 : x
2. Step 2: Convert to fraction form
   64,857/139,719 = 139,719/x
3. Step 3: Cross multiply
   64,857x = 139,719 × 139,719
4. Step 4: Simplify right side
   64,857x = 19,521,398,961
5. Step 5: Solve for x
   x = 19,521,398,961/64,857
6. Step 6: Final answer
   x = 300,991.40