Finding the Third Proportional to 139.38 and 204.31

Step by Step Solution

1. Step 1: Write the proportion equation
   139.38 : 204.31 = 204.31 : x
2. Step 2: Convert to fraction form
   139.38/204.31 = 204.31/x
3. Step 3: Cross multiply
   139.38x = 204.31 × 204.31
4. Step 4: Simplify right side
   139.38x = 41,743.60
5. Step 5: Solve for x
   x = 41,743.60/139.38
6. Step 6: Final answer
   x = 299.51