Finding the Fourth Proportional to 142.56, 196.56 and 120.96

Step by Step Solution

1. Step 1: Write the proportion equation
   142.56 : 196.56 = 120.96 : x
2. Step 2: Convert to fraction form
   142.56/196.56 = 120.96/x
3. Step 3: Cross multiply
   142.56x = 196.56 × 120.96
4. Step 4: Simplify right side
   142.56x = 23,775.90
5. Step 5: Solve for x
   x = 23,775.90/142.56
6. Step 6: Final answer
   x = 166.78