Finding the Fourth Proportional to 142.46, 196.42 and 139.42

Step by Step Solution

1. Step 1: Write the proportion equation
   142.46 : 196.42 = 139.42 : x
2. Step 2: Convert to fraction form
   142.46/196.42 = 139.42/x
3. Step 3: Cross multiply
   142.46x = 196.42 × 139.42
4. Step 4: Simplify right side
   142.46x = 27,384.88
5. Step 5: Solve for x
   x = 27,384.88/142.46
6. Step 6: Final answer
   x = 192.23