Finding the Fourth Proportional to 139.72, 209.10 and 96.18

Step by Step Solution

1. Step 1: Write the proportion equation
   139.72 : 209.10 = 96.18 : x
2. Step 2: Convert to fraction form
   139.72/209.10 = 96.18/x
3. Step 3: Cross multiply
   139.72x = 209.10 × 96.18
4. Step 4: Simplify right side
   139.72x = 20,111.24
5. Step 5: Solve for x
   x = 20,111.24/139.72
6. Step 6: Final answer
   x = 143.94