Finding the Fourth Proportional to 142.72, 196.52 and 139.68

Step by Step Solution

1. Step 1: Write the proportion equation
   142.72 : 196.52 = 139.68 : x
2. Step 2: Convert to fraction form
   142.72/196.52 = 139.68/x
3. Step 3: Cross multiply
   142.72x = 196.52 × 139.68
4. Step 4: Simplify right side
   142.72x = 27,449.91
5. Step 5: Solve for x
   x = 27,449.91/142.72
6. Step 6: Final answer
   x = 192.33