Finding the Fourth Proportional to 142.56, 196.72 and 87.32

Step by Step Solution

1. Step 1: Write the proportion equation
   142.56 : 196.72 = 87.32 : x
2. Step 2: Convert to fraction form
   142.56/196.72 = 87.32/x
3. Step 3: Cross multiply
   142.56x = 196.72 × 87.32
4. Step 4: Simplify right side
   142.56x = 17,177.59
5. Step 5: Solve for x
   x = 17,177.59/142.56
6. Step 6: Final answer
   x = 120.49