Finding the Fourth Proportional to 144.82, 216.72 and 139.15

Step by Step Solution

1. Step 1: Write the proportion equation
   144.82 : 216.72 = 139.15 : x
2. Step 2: Convert to fraction form
   144.82/216.72 = 139.15/x
3. Step 3: Cross multiply
   144.82x = 216.72 × 139.15
4. Step 4: Simplify right side
   144.82x = 30,156.59
5. Step 5: Solve for x
   x = 30,156.59/144.82
6. Step 6: Final answer
   x = 208.23