Finding the Third Proportional to 67,778 and 139,660

Step by Step Solution

1. Step 1: Write the proportion equation
   67,778 : 139,660 = 139,660 : x
2. Step 2: Convert to fraction form
   67,778/139,660 = 139,660/x
3. Step 3: Cross multiply
   67,778x = 139,660 × 139,660
4. Step 4: Simplify right side
   67,778x = 19,504,915,600
5. Step 5: Solve for x
   x = 19,504,915,600/67,778
6. Step 6: Final answer
   x = 287,776.50