Finding the Fourth Proportional to 144.72, 215.82 and 139.32

Step by Step Solution

1. Step 1: Write the proportion equation
   144.72 : 215.82 = 139.32 : x
2. Step 2: Convert to fraction form
   144.72/215.82 = 139.32/x
3. Step 3: Cross multiply
   144.72x = 215.82 × 139.32
4. Step 4: Simplify right side
   144.72x = 30,068.04
5. Step 5: Solve for x
   x = 30,068.04/144.72
6. Step 6: Final answer
   x = 207.77