Finding the Fourth Proportional to 139.33, 208.56 and 137.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139.33 : 208.56 = 137.50 : x
2. Step 2: Convert to fraction form
   139.33/208.56 = 137.50/x
3. Step 3: Cross multiply
   139.33x = 208.56 × 137.50
4. Step 4: Simplify right side
   139.33x = 28,677
5. Step 5: Solve for x
   x = 28,677/139.33
6. Step 6: Final answer
   x = 205.82