Finding the Fourth Proportional to 142.18, 196.28 and 105.42

Step by Step Solution

1. Step 1: Write the proportion equation
   142.18 : 196.28 = 105.42 : x
2. Step 2: Convert to fraction form
   142.18/196.28 = 105.42/x
3. Step 3: Cross multiply
   142.18x = 196.28 × 105.42
4. Step 4: Simplify right side
   142.18x = 20,691.84
5. Step 5: Solve for x
   x = 20,691.84/142.18
6. Step 6: Final answer
   x = 145.53