Finding the Third Proportional to 139.78 and 246.38

Step by Step Solution

1. Step 1: Write the proportion equation
   139.78 : 246.38 = 246.38 : x
2. Step 2: Convert to fraction form
   139.78/246.38 = 246.38/x
3. Step 3: Cross multiply
   139.78x = 246.38 × 246.38
4. Step 4: Simplify right side
   139.78x = 60,700.64
5. Step 5: Solve for x
   x = 60,700.64/139.78
6. Step 6: Final answer
   x = 434.25