Finding the Fourth Proportional to 139.52, 209.52 and 137.96

Step by Step Solution

1. Step 1: Write the proportion equation
   139.52 : 209.52 = 137.96 : x
2. Step 2: Convert to fraction form
   139.52/209.52 = 137.96/x
3. Step 3: Cross multiply
   139.52x = 209.52 × 137.96
4. Step 4: Simplify right side
   139.52x = 28,905.38
5. Step 5: Solve for x
   x = 28,905.38/139.52
6. Step 6: Final answer
   x = 207.18