Finding the Fourth Proportional to 144.30, 214.71 and 139.98

Step by Step Solution

1. Step 1: Write the proportion equation
   144.30 : 214.71 = 139.98 : x
2. Step 2: Convert to fraction form
   144.30/214.71 = 139.98/x
3. Step 3: Cross multiply
   144.30x = 214.71 × 139.98
4. Step 4: Simplify right side
   144.30x = 30,055.11
5. Step 5: Solve for x
   x = 30,055.11/144.30
6. Step 6: Final answer
   x = 208.28